Bensulide Human Health Risk Assessment DP No

. D428598

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON

, D.C. 20460

MEMORANDUM

Date: 03/03/2016 OFFICE OF

CHEMICAL SAFETY AND

POLLUTIO N PREVENTION

SUBJECT: Bensulide. Human Health Risk Assessment to Support Registration Review.

PC Code: 009801

Decision No.: 507866

Petition No.: NA

Risk Assessment Type: Single chemical/aggregate

TXRNo.: NA

MRIDNo.: NA

FROM: DP Barcode: D428598 Registration No.: 10163-200 Regulatory Action: Registration Review

Case No.: 2035

CAS No.: 741-58-2

40 CFR: 180.241

TO: Margaret Hathaway

, Chemical Review Manger Cathryn Britton

, Team Leader

Kevin Costello

, Branch Chief

Pesticide Re-evaluation Division (PRD ; 7508P)

Page 1 of97Bensulide Human Health Risk Assessment DP No. D428598

Page 2 of 97 1.0 Executive Summary ................................................................................................... 4

2.0 HED Recommendations ............................................................................................ 7

2.1 Data Deficiencies ........................................................................................................ 7

2.2 Tolerance Considerations ......................................................................................... 8

2.2.1 Enforcement Analytical Method .............................................................................. 8

2.2.2 Recommended Tolerances ........................................................................................ 8

2.2.3 International Harmonization .................................................................................... 9

2.3 Label Recommendations ........................................................................................... 9

2.3.1 Recommendations from Residue Reviews ............................................................... 9

2.3.2 Recommendations from Occupational Assessment ................................................ 9

2.3.3 Recommendations from Residential Assessment .................................................. 10

3.0 Introduction .............................................................................................................. 10

3.1 Chemical Identity ..................................................................................................... 10

3.2 Physical/Chemical Characteristics ......................................................................... 10

3.3 Pesticide Use Pattern ............................................................................................... 11

3.4 Anticipated Exposure Pathways ............................................................................. 13

3.5 Consideration of Environmental Justice ............................................................... 13

4.0 Hazard Characterization and Dose-Response Assessment .................................. 14

4.1 Toxicology Studies Available for Analysis ............................................................ 14

4.2 Absorption, Distribution, Metab olism, and Elimination (ADME) ..................... 15

4.2.1 Dermal Absorption .................................................................................................. 15

4.3 Toxicological Effects ................................................................................................ 15

4.3.1 Critical Durations of Exposure ............................................................................... 17

4.4 Literature Review on Ne urodevelopment Effects ................................................. 18

4.5 Safety Factor for Infants and Children (FQPA SF) ............................................. 24

4.5.1 Completeness of the Toxicology Database ............................................................. 24

4.5.2 Evidence of Neurotoxicity ....................................................................................... 24

4.5.3 Evidence of Sensitivity/Susceptibility in the Developing or Young Animal ....... 24

4.5.4 Residual Uncertainty in the Exposure Database .................................................. 25

4.6 Toxicity Endpoint and Point of Departure Selections .......................................... 25

4.6.1 Dose-Response Assessment ..................................................................................... 25

4.6.2 Oxon Toxicity Adjustment Factor ......................................................................... 28

4.6.3 Recommendation for Combining Routes of Exposures for Risk Assessment .... 29

4.6.4 Cancer Classification and Risk Assessment Recommendation ........................... 29

4.6.5 Summary of Points of Departure and T oxicity Endpoints Used in Human Risk

Assessment ................................................................................................................ 30

4.7 Endocrine Disruption .............................................................................................. 32

5.0 Dietary Exposure and Risk Assessment ................................................................ 33

5.1 Residues of Concern Summary and Rationale ..................................................... 33

5.2 Food Residue Profile ................................................................................................ 33

5.3 Water Residue Profile ............................................................................................. 34

5.4 Dietary Risk Assessment ......................................................................................... 35

5.4.1 Description of Residue Data Used in Dietary Assessment ................................... 35

5.4.2 Percent Crop Treated Used in Dietary Assessment .............................................. 36

5.4.3 Acute Dietary Risk Assessment .............................................................................. 36Bensulide Human Health Risk Assessment DP No. D428598

Page 3 of 97 5.4.4 Steady-state Dietary Risk Assessment ................................................................... 37

5.4.5 Cancer Dietary Risk Assessment ............................................................................ 37

5.4.6 Summary Tables ...................................................................................................... 37

6.0 Residential (Non-Occupational) Exposure/Risk Characterization ..................... 38

6.1 Residential Handler Exposure ................................................................................ 38

6.2 Residential Post-Application Exposure ................................................................. 41

6.4 Residential Risk Estimates fo r Use in Aggregate Assessment ............................. 44

6.5 Residential Bystander Post-application Inhalation Exposure ............................. 44

6.6 Non-Occupational Spray Drift Exposure and Risk Estimates ............................ 45

7.0 Aggregate Exposure/Risk Characterization .......................................................... 50

7.1 Acute Aggregate Risk .............................................................................................. 50

7.2 Steady-state Aggregate Risk ................................................................................... 50

7.3 Cancer Aggregate Risk ............................................................................................ 50

8.0 Cumulative Exposure/Risk Characterization ....................................................... 50

9.0 Occupational Exposure/Risk Characterization .................................................... 51

9.1 Steady-State Handler Risk ...................................................................................... 51

9.2 Steady-State Post-Application Risk ....................................................................... 57

9.2.1 Dermal Post-Application Risk ................................................................................ 57

9.2.2 Inhalation Post-Application Risk ........................................................................... 59

10.0 Public Health and Pesticide Epidemiology Data ................................................... 60

11.0 References ................................................................................................................. 61 Appendix A. Toxicology Prof ile and Executive Summaries .................................................. 64

A.1 Toxicology Data Requirements .............................................................................. 64

A.2 Summary of OPP’s ChE Policy & Use of BMD Modeling ................................... 65

A.3 Executive Summaries .............................................................................................. 73 Appendix B. Physical/Chemical Properties ............................................................................. 94 Appendix C. Review of Human Research ................................................................................ 95 Appendix D. International Residue Limits Table ................................................................... 96 Appendix E. Comparison of Residue Levels of Bensulide and its Oxon .............................. 97Bensulide Human Health Risk Assessment DP No. D428598

Page 4 of 97 1.0 Executive Summary

Bensulide is an organophosphate (OP) herbicide registered for food/feed uses on bulb onion, garlic, shallots, leafy vegetable except brassi ca (crop group (CG) 4), l eafy brassica vegetable (CG 5), fruiting vegetable (CG 8), cucurbit vegeta ble (CG 9), and a regional registration for use on carrots. Tolerances ranging from 0.10 to 0.15 ppm are established in the 40 CFR §180.241 for residues of bensulide, including its oxygen analog, in/on these raw agricultural commodities (RACs). The emulsifiable concentrate (EC) end-use product Prefar 4E (EPA Reg. No. 10163- 200) is the only bensulide end-use product regi stered for use on food/feed crops, which is typically applied to the soil pr eplant or preemergence using ground equipment. In addition,

bensulide is used for weed control in residentia l and occupational settings, and can be applied to golf courses and residential turf. Based on the registered use patte rn for bensulide, humans may be exposed to bensulide in food and drinking water. Dermal and i nhalation exposures are anticipated for residential and o ccupational handlers. In additi on, dermal and incidental oral exposures are anticipated from post-application activities occurring in tr eated areas. There is also the potential for non-occupational expos ure as a result of spray drift.

Hazard Assessment

Bensulide is a member of the or ganophosphate class of pesticides. Like other OPs, the initiating

event in the adverse outcome pathway (AOP)/ mode of action (MOA) for bensulide involves inhibition of the enzyme acetylcholinesterase (A ChE) via phosphorylation of the serine residue at the active site of the enzy me. This inhibition leads to ac cumulation of acetylcholine and ultimately to neurotoxicity in the central and/or peripheral nervous system. For bensulide, AChE inhibition is the most sensitive endpoint in the to xicology database in multiple species, durations, lifestages, and routes. Bensulide requires metabolic activation to an oxon to effectively inhibit AChE. OPs also exhibit steady-state AChE inhi bition. After repeated do sing at the same dose level, the degree of inhibition comes into equilibrium with th e production of new, uninhibited enzyme. As such, the endpoint selection for be nsulide focuses on acute, single day effects and steady-state effects.

The toxicology database for be nsulide is complete for risk assessment, except for the requirement of a repeat dose inhalation toxicity study (Leshin, 2015, TXR # 0057280) and bensulide oxon comparative cholin esterase assays (CCA). Appr opriate database uncertainty factors are applied for the lack of the inhalation study, and the oxon is considered to be 50X as potent as the parent in the absence of data (see section 4.6.2 for the rationale for 50X).

Bensulide has high quality dose-response data across multiple lifestages and durations via the oral route for both red blood cell (RBC) and br ain AChE inhibition (ChEI). Dermal routespecific endpoints could not be evaluated using benchmark dose (BMD) analysis, since the ChEI data from the dermal toxicity study would not model (no apparent dose response). An inhalation study is not available. Clinical si gns of neurotoxicity, su ch as tremor, occur at doses much higher than those causing inhibition of AChE.

The RBC AChE was generally more sensitive than the brain AChE to bensulide. The available AChE data across multiple lifestages (adults, pregna nt adults, fetuses, juveniles) demonstrate that the PND 11 pups were generally more sensitive than the adult. In the gestational CCA, the fetusBensulide Human Health Risk Assessment DP No. D428598

Page 5 of 97 was not more sensitive than the dam. The pregna nt female in the gestational CCA was not more sensitive than the non-pregnant female in the re peated dose CCA. The adult female was typically more sensitive than the adult male, while the pup and fetus did not demonstrate sex-sensitivity.

Bensulide is classified as “not likely to be carcinogenic in humans”, based on an absence of significant tumor increases in two adequate rode nt carcinogenicity stud ies. A quantitative cancer risk assessment is not required. In acute oral lethality st udies, bensulide is Toxicity Category II. The acute lethal toxicity is low for other rout es, Toxicity Category III or IV for dermal and inhalation toxicity; and dermal and eye irri tation. It is not a dermal sensitizer.

Endpoints and Uncertainty Factors for Risk Assessment: The endpoint for all exposure scenarios is RBC ChEI and points of departure (PODs) were selected from high quality, wellconducted CCA rat studies. A POD for the acute di etary (all populations) exposure scenario was 11 mg/kg/day; the POD for the steady-state diet ary exposure, incident al oral, dermal, and inhalation scenarios was 6 mg/kg/day. The FQPA safety factor (10X) ha s been retained for infants, children, youths, and women of child-b earing age for all expo sure scenarios (both occupational and residential) due to uncertainty in the human dose-response relationship for neurodevelopmental effects (see section 4.4). Add itionally, for inhalation exposures, a database uncertainty factor of 30X was applied due to unc ertainty in the human dose-response relationship for neurodevelopmental effects and lack of an inhalation toxicity study. For all exposure scenarios, interspecies (10X) a nd intraspecies (10X) uncertainty factors were applied in addition to the FQPA safety factor. As a result, a tota l uncertainty factor of 1000X was applied for all non-cancer exposure scenarios, exce pt dietary exposures for the adult population subgroup 50-99 years old (total uncertainty fact or = 100X) and inhalation exposure s (total uncertainty factor = 3000X).

Dietary Exposure and Risk Acute and steady state dietary exposure assessmen ts incorporated USDA Pe sticide Data Program (PDP) monitoring data for bensulide and its oxon (w hen available), anticipat ed residues, default DEEM processing factors, and percent crop trea ted (CT) data. The Environmental Fate and Effects Division (EFED) provided daily time seri es outputs for the scenarios that provide the highest and lowest estimated drinking water concentrations (EDWC); groundwater in North Carolina Eastern Coastal Plain (C otton) and surface water in Calif ornia (Avocado), respectively. These concentrations were reported as the oxon a nd converted to bensulide using a 50x factor.

Acute Dietary Exposure Assessment: Acute dietary assessments were conducted for food only, water only, and food and drinking water. The ac ute dietary exposure estimates from food alone are below HED’s level of concern (<100 % of th e acute population adjusted dose (aPAD)) at the

99.9 th percentile of exposure, e.g. 46% of the aPAD for the most highly exposed population subgroup, children 3-5 years old. For food and dr inking water, the dietary exposure is >10,000% and >1,600% of the aPAD at the 99.9 th percentile of exposure using drinking water scenarios that provided the highest and lowest EDWC, respectively. Although fo r Adults 50-99 years old the FQPA SF is 1x, exposures were also of concern for food and drinking water.

Steady-state Dietary Exposure Assessment: Steady-state assessments were conducted for food only, water only, and food and drinking water. The steady-state dietary exposure estimates fromBensulide Human Health Risk Assessment DP No. D428598

Page 6 of 97 food alone are below HED’s level of concern (< 100 % of the steady-st ate population adjusted dose (ssPAD) at the 99.9 th percentile of exposure, e.g. 80% of the ssPAD for the most highly exposed population subgroup, children 3-5 years old. For food and drinking water, the dietary exposure is >10,000% and >2,900% of the ssPAD at the 99.9 th percentile of exposure using drinking water scenarios that provided the highest and lowest EDWC, respectively. Although for Adults 50-99 years old the FQPA SF is 1x, exposur es were also of concern for food and drinking

water.

Residential Exposure and Risk

Residential handler risk estimat es for applying liquid and granul e products to residential lawns are of concern at currently labeled use rates. For residential handlers, a total aggregated risk index (ARI) was used since the LOCs for de rmal exposure (1000) and inhalation exposure (3000) are different. The target ARI is 1; theref ore, ARIs of less than 1 are risk estimates of concern. Residential post-applica tion risk estimates for turf uses were assessed using chemicalspecific turf transferable resi due (TTR) data for a liquid fo rmulation, and accounting for the difference in toxicity between the parent, bensu lide, and the oxon (i.e., by applying a 50x toxicity adjustment factor). Risk estim ates are of concern for dermal exposure for adults and children conducting activities on trea ted turf; for dermal exposure for a dults and youths golfing; for handto-mouth exposure for children on treated turf; a nd for episodic granule ingestion exposure.

Non-Occupational Exposure and Risk (Spr ay Drift and Bystander Volatilization) Spray Drift: Risk estimates related to spray drift ar e of concern at various distances from the edge of the field for adults and children (1 to <2 years) depending on th e spray drift scenario. For adults, the screening level scenario indicates the LOC is exceeded at a distance of less than 25 feet for applications to vegeta bles and less than 75 feet for app lications to golf courses. For children, the screening level scenario indicates th e LOC is exceeded at a distance of less than 75 feet for applications to vegetabl es and less than 150 feet for app lications to golf courses. Drift reduction technologies, such as using coarser sprays and lowering boom height for groundboom sprayers, reduces risk concerns; however, there ar e still risk estimates of concern at the field edge in some cases.

Volatilization/Resi dential Bystander: Volatilization of pesticides may be a source of postapplication inhalation exposure to individuals nearby pe sticide applications. The Agency has developed a Volatilization Screen ing Tool and a subsequent Vola tilization Screening Analysis, and during Registration Review, the Agency will uti lize this analysis to determine if data (i.e., flux studies) or further analyses are required for bensulide.

Aggregate Exposure and Risk

Because there are risks of concern for the resi dential and drinking wate r exposure scenarios, a steady-state aggregate assessment was not conducte d. The acute aggregate assessment consists of exposure through food and drinking water and is , therefore, reflecte d by the acute dietary

exposure assessment.

Occupational Exposure and Risk Occupational handler risk estimates (combined dermal + inhalation) were calculated for the registered uses on golf courses, turf, and ve getable crops. With the label-required personalBensulide Human Health Risk Assessment DP No. D428598

Page 7 of 97 protective equipment (PPE), all combined handler risk estimates are of concern. Even with applying maximum PPE or engineering controls , many occupational hand ler risk estimates remain of concern. Since bensulide is applied to vegetables as a pr eplant or preemergence application only, occupational post- application dermal exposures are not anticipated for these uses. A quantitative occupationa l dermal post-application exposur e assessment was, therefore, only conducted for the registered golf course use. Occupationa l post-application dermal risk estimates during maintenance activities on golf c ourses were of concern (i.e., MOEs are < 1,000) until 5 days after treatment.

Human Studies Review This risk assessment relies in part on data from studies in which adult human subjects were intentionally exposed to a pest icide or other chemical. Addi tional information on how these

studies are considered ca n be found in Appendix C.

2.0 HED Recommendations

The hazard/toxicity, residue chemistry, occupati onal and residential databases are considered complete with the exception of th e data requirements specified in Section 2.1. In addition, label

recommendations are discussed in section 2.3.

2.1 Data Deficiencies

Hazard/Toxicity: A repeat dose inhalati on toxicity study (Leshi n, 2015, TXR # 0057280) and bensulide oxon comparative cholineste rase assays (CCA) are required.

Residue Chemistry: (1) Three geographically representative field trials on non-bell peppers are required. Pending the submission of these data, the instructions for application to non-bell peppers should be removed from the label. This data deficiency was identified in the bensulide residue chemistry chapter in support of the Re gistration Eligibility Decision (RED; C. Eiden, D238417, 10/06/1997) and the registration revi ew scoping document (T. Goodlow, D347549, 06/10/2008). (2) Twelve crop field trials for bensulide on tomato grown in Mexico were required in the bensulide residue chemistry chapter in support of the Registration Eligibility Decision (RED; C. Eiden, D238417, 10/06/1997). Th e label from Mexico was submitted and describes a similar use pattern with the one regist ered in the US. The re gistrant expressed their intent to submit a proposal to address this data gap (conference cal l on 11/16/2015, coordinated by Margaret Hathaway). Pending the submission of these data, the twelve crop field trials are still required.

Occupational and Residential: There are no data deficienci es. Chemical-specific turf transferable residue (TTR) data are available; DF R data are not required based on the registered

use pattern.Bensulide Human Health Risk Assessment DP No. D428598

Page 8 of 97 2.2 Tolerance Considerations

2.2.1 Enforcement Analytical Method

Adequate methods are available for tolerance enforcement for plant commodities. The Pesticide Analytical Manual (PAM) Vol. II lists Gas Ch romatography (GC) Method I, using either phosphorus-sensitive thermionic de tection or flame photometric de tection, for the determination of bensulide and bensulide oxygen analog in pl ant commodities. Thin layer chromatography (TLC) Method A is available for confirmation. Moreover, the PAM (Volume I, Appendix I) indicates that bensulide is recovered using Mu ltiresidue Methods Sections 302 (Luke Method; Protocol D), 304 (Mills Method; Protocol E, fatty foods) and 303 (Mills, Onley, Gaither Method; Protocol E, non-fatty foods). No information re garding the recovery of bensulide oxygen analog using Multiresidue Methods is in cluded in the PESTDATA database.

2.2.2 Recommended Tolerances

HED recommends modifying the tolerance expr ession and crop groups in cluded in the CFR for bensulide. The tolerance expres sions in the 40 CFR § 180.241 (a) and (c) need to be modified to include both coverage and comp liance statements for enforcement purposes, as recommended in the Interim Guidance on Writing Tolerance Expressions (S. Knizner, 05/27/2009). The recommended tolerance expressions are:

(a) General. “Tolerances are established for residues of the herbicide bens ulide, including its metabolites and degradates, in or on the commoditi es in the following table. Compliance with the tolerance levels specified in the table below is to be determined by measuring only bensulide, S- (O,O-diisopropyl phosphorod ithioate) ester of N-(2-mercaptoet hyl) benzenesulfonamide, and its oxygen analog, S-(O,O-diisopropyl phosphorot hioate) of N-(2-mercaptoethyl) benzenesulfonamide, in or on the commodity.”

(c) Tolerance with regional registration. “Tolerances with regional registration, as defined in §180.1(l), are established for residue s of the herbicide bensulide, including its metabolites and degradates, in or on the commodities in the followi ng table. Compliance with the tolerance levels specified in the table below is to be determin ed by measuring only bensulide, S-(O,O-diisopropyl phosphorodithioate) ester of N-(2-mercaptoethyl ) benzenesulfonamide, and its oxygen analog, S- (O,O-diisopropyl phosphorothioate ) of N-(2-mercaptoethyl) benzenesulfonamide, in or on the commodity.”

Since non-bell pepper field trial data are not available, HED c oncludes that th e tolerance for fruiting vegetable crop group 8 should be dele ted and those for bell pepper and tomatillo established in support of domestic registrations . Additional data are required to support a tolerance for tomato imported from Mexico. The establishment of a tolerance for tomato may be recommended if these data (or registrant pr oposal) are received from the registrant and considered adequate to support this use. To lerances included in the 40 CFR 180.241 need to be modified as specified in the table below.Bensulide Human Health Risk Assessment DP No. D428598

Page 9 of 97 Table 2.2.2. Tolerance Summary for Bensulide. Commodity Established Tolerance (ppm) HED-Recommended Tolerance (ppm) Comments ( correct commodity definition ) Vegetable, fruiting, group 8 0.10 Remove Pepper, bell None 0.10

Tomatillo None 0.10 Tomato, subgroup 8-10A* None 0.10 *May be established pending review of required data in support of import use.

2.2.3 International Harmonization

There are no Codex, Mexican or Canadian maximu m residue limits established for bensulide. Therefore, harmonization is not germane to this assessment.

2.3 Label Recommendations

2.3.1 Recommendations from Residue Reviews

A summary of the risk estimates has been pr ovided, and shows that there are dietary risk estimates of concern for registered uses of be nsulide. The following recommendations are based

on the review of the label of bensulide’s end use product Prefar 4-E (EPA Reg. No. 10163-200, 12/13/2013):

 The current label of Prefar 4-E includes inst ructions for use on non-bell peppers such as chili peppers, cooking peppers, pimentos and sweet peppers. A magnitude of residue study for bensulide in/on non-bell peppers ha s been required in the RED and scoping document. Alternatively, it was indicated that the registrant could restrict use to bell peppers. Since these data ha ve not been received, HED recommends that the bensulide product label restrict the use to only bell pepp ers. Moreover, reference to the fruiting vegetables crop group needs to be removed.

 The maximum seasonal application rate for cucurbit vegetables, tomatillo and bell peppers needs to be specified on the label of Prefar 4-E. A maximum seasonal application rate of 6 lbs a i/A is supported by adequate data for crops under these crop

groups.

2.3.2 Recommendations from Occupational Assessment

No label recommendations based on the occupa tional assessment have been identified. A summary of the risk estimates has been provide d, and shows that there are risk estimates of concern for registered uses of bensulide ba sed on the use information, label-required personal protective equipment (PPE), and REIs (golf course uses only).Bensulide Human Health Risk Assessment DP No. D428598

Page 10 of 97 2.3.3 Recommendations from Residential Assessment

No label recommendations based on the residential assessment have been identified. A summary of the risk estimates has been provided, and show s that there are risk estimates of concern for registered uses of bensulide based on the current use information.

3.0 Introduction

3.1 Chemical Identity

Table 3.1. Bensulide and Bensulide Oxon Nomenclature. Compound Chemical Structure

Common name Bensulide IUPAC name O,O-diisopropyl-S-2-phenylsulfonylaminoethylphosphorodithioate CAS name S-(O,O-diisopropyl phosphorodithioate) ester of N-(2-mercaptoethyl)

benzenesulfonamide

CAS # 741-58-2
Compound Chemical Structure

Common name Bensulide Oxon IUPAC name O,O-diisopropyl-S-2-phenylsulfonylaminoethylphosphorothioate CAS name S-(O,O-diisopropyl phosphorothioate) of N-(2-mercaptoethyl)

benzenesulfonamide

CAS # 20243-81-6

3.2 Physical/Chemical Characteristics

The physicochemical properties of bensulide and its oxon are summarized in Appendix B. Bensulide (5.6 mg/L) is moderately soluble in water; however, it is less soluble than its oxon (461 mg/L, EPISuite v. 4.10). Both compounds have low volatility and the oxon has a low partition coefficient. Bensulide is sligh tly mobile in the four soils tested (K oc 's ranged from 1,433 to 4,326 mL/g) based on an acceptable stu dy; however, its major degradate bensulide oxon (average K oc = 557) ranged from moderately mobile to highl y mobile in the same four test soils.Bensulide Human Health Risk Assessment DP No. D428598

Page 11 of 97 3.3 Pesticide Use Pattern

Bensulide is used for weed control in resident ial and occupational settings. Bensulide can be applied to vegetable crops, golf courses, and residential turf. Pref ar 4 E (EPA Reg. No. 10163- 200) is the only bensulide end-use product re gistered for food uses on bulb onion, garlic, shallots, leafy vegetable except brassica (CG 4) , leafy brassica vegetables (CG 5), fruiting vegetable (CG 8), cucurbit vegetables (CG 9), regi onal use on carrots grown in Texas, as well as non-food uses on golf courses and home lawns. A summary of bensulide uses is listed in Table

3.3.

Table 3.3. Summary of Direct ions for Use of Bensulide.

Applic. Timing, Type, and

Equip. Formulation [EPA Reg. No.] Applic. Rate (lb

ai/A) Max.

Seasonal Applic. Rate

(lb ai/A) PHI (days) Use Directions and Limitations

Turf (Golf Courses and Residential Lawns)

Groundboom or

low pressure

turfgun,

Handwand for

spot treatment

Watered in Liquid 4 lb ai/gal (46% ai) EPA Reg. No.

2217-696 12.5 lb

ai/acre 25 lb ai/acre NA PPE: baseline, gloves, PF5 respirator

Tractor drawn spreader, Push type spreader

Watered in Granular

7% ai EPA Reg. No.

2217-778 12.6 lb

ai/acre 25.2 lb

ai/acre NA PPE: Loaders, spreader applicator: Coveralls, gloves, PF5 respirator All others: baseline, gloves For hire applicators must wear PF5 respirator Cannot be applied aerially

Only on lawns

Push type spreader only Granular

3.6% ai EPA Reg. No.

2217-838 12.5 lb

ai/acre NA NA No PPE listed Hand-held rotary broadcast spreader prohibited

Tractor drawn spreader, push type spreader Granular

8.5% ai EPA Reg. No

9198-172 12.4 lb

ai/acre NA NA PPE: loaders, spreader applicator: coveralls, gloves, PF5 respirator

All others: baseline, gloves

Golf courses only

Tractor drawn spreader or push

type spreader

Watered in Granular

5.25% ai EPA Reg. No.

9198-176 16 lb ai/acre 32 lb ai/acre NA Not for sale or use by homeowners PPE: push spreaders and loader: coveralls, gloves, PF5 respirator Other applicators: baseline, gloves For hire applicators must wear PF5 respirator Golf courses only Groundboom, low pressure turfgun,

LP Handwand for

spot treatment Liquid

46.4% ai 4 lb ai/gal EPA Reg. No.

10163-196 12.5 lb

ai/acre 25 lb ai/acre NA PPE: Mixer/loader: baseline, gloves, PF5 respirator Applicator and other: baseline, gloves; for hire applicators must wear PF5 respirator

Golf courses only

Watered in Granular

12.5% ai EPA Reg. No.

10163-198 12.5 lb

ai/acre 25 lb ai/acre NA PPE: Loaders, spreader applicator: coveralls, gloves, respirator Other applicators: baseline, gloves, respirator Golf courses only

Tractor drawn Granular

3.6% ai 12.5 lb

ai/acre NA NA PPE: Loaders and spreader applicators: coveralls, gloves,Bensulide Human Health Risk Assessment DP No. D428598

Page 12 of 97 Table 3.3. Summary of Direct ions for Use of Bensulide.

Applic. Timing, Type, and

Equip. Formulation [EPA Reg. No.] Applic. Rate (lb

ai/A) Max.

Seasonal Applic. Rate

(lb ai/A) PHI (days) Use Directions and Limitations

spreader or pushtype spreader

Watered in EPA Reg. No.

10163-199 eyewear, for-hire applicators must wear respirator All other applicators: baseline, gloves, respirator Hand-held rotary spreaders are prohibited Golf courses only

Tractor drawnspreader or pushtype spreader

Watered in Granular

7% ai EPA Reg. No.

10163-204 12.6 lb

ai/acre 25 lb ai/acre NA PPE: loaders and spreader applicators: coveralls, gloves, respirator; others: baseline, gloves,

for-hire applicators must wear respirator

Residential lawns only

RTU Garden hose

sprayer 46.4% ai EPA Reg. No.

10163-205 16 fl oz product/ 2500 sq. ft

8.7 lb ai/A NA NA No PPE listed

Cucurbit vegetables

Groundboom, Chemigation,

Handgun

Preplant or

preemergence Emulsifiable Liquid 4 lb ai/gal EPA Reg. No.

10163-200 6 lb ai/acre NA NA PPE: baseline, gloves; Mixers, loaders and commercial applicators must wear a PF5 respirator May not be applied by aircraft

9 lb ai/acre NA NA SLN label – CA 960003

Brassica (cole) leafy vegetables; leafy vegetables

Groundboom, Chemigation,

Handgun

Preplant or

preemergence Emulsifiable Liquid 4 lb ai/gal EPA Reg. No.

10163-200 6 lb ai/acre 6 lb ai/acre NA PPE: baseline, gloves; Mixers, loaders and commercial applicators must wear a PF5 respirator Do not use on spinach or Swiss

Chard May not be applied by aircraft

9 lb ai/acre 9 lb ai/acre NA SLN label – NJ 070001

Fruiting vegetables
Groundboom, Chemigation,

Handgun

Preplant or

preemergence Emulsifiable Liquid 4 lb ai/gal EPA Reg. No.

10163-200 6 lb ai/acre NA NA PPE: baseline, gloves; Mixers, loaders and commercial applicators must wear a PF5 respirator May not be applied by aircraft

Carrots
Groundboom, Chemigation,

Handgun

Preplant or Preemergence Emulsifiable Liquid 4 lb ai/gal EPA Reg. No.

10163-200 5 lb ai/acre 5 lb ai/acre NA PPE: baseline, gloves; Mixers, loaders and commercial applicators must wear a PF5 respirator May not be applied by aircraft

Dry Bulb Vegetables
Groundboom, Chemigation,

Handgun Emulsifiable Liquid 4 lb ai/gal 6 lb ai/acre 6 lb ai/acre NA PPE: baseline, gloves; Mixers, loaders and commercial applicators must wear a PF5 respiratorBensulide Human Health Risk Assessment DP No. D428598

Page 13 of 97 Table 3.3. Summary of Direct ions for Use of Bensulide.

Applic. Timing, Type, and

Equip. Formulation [EPA Reg. No.] Applic. Rate (lb

ai/A) Max.

Seasonal Applic. Rate

(lb ai/A) PHI (days) Use Directions and Limitations

Preplant or Preemergence EPA Reg. No.

10163-200 May not be applied by aircraft

NA = Not Applicable for preplant applicati on or application preemergence of the crop.

3.4 Anticipated Exposure Pathways

Humans may be exposed to bensulide in food a nd drinking water because this chemical may be applied directly to growing cr ops and application may result in bensulide reaching surface and ground water sources of drinking water. Conve rsion of bensulide into bensulide oxon (13.8%)

has been observed under aerobic soil conditions while bensulide ma y be totally converted into bensulide oxon during the chlorination processe s (Kamel et al.; 2009). Moreover, the oxon has been observed in samples of lettuce and carrot. Th ere are residential uses of bensulide for weed control; residential handlers may be exposed dur ing application, and adults and children may be exposed after application in treat ed areas. In an occupational se tting, applicators may be exposed while handling the pesticide prior to application, as well as duri ng application. Since bensulide is applied to crops preplant or preemergence, occupational po st-application exposure is not anticipated from those registered uses. Howe ver, there is a potential for post-application exposure for workers performing activiti es in treated golf courses.

3.5 Consideration of Environmental Justice

Potential areas of environmental ju stice concerns, to the extent possi ble, were considered in this human health risk assessment, in accordance w ith U.S. Executive Order 12898, "Federal Actions

to Address Environmental Just ice in Minority Populations an d Low-Income Populations," ( http://www.archives.gov /federal-register/ex ecutive-orders/pdf/12898.pdf ). As a part of every pesticide risk assessment, OPP considers a larg e variety of consumer subgroups according to well-established procedures. In line with OPP policy, HED estimates risks to population subgroups from pesticide exposures that are based on patterns of that subgroup’s food and water consumption, and activities in and around the home that involve pesticide use in a residential setting. Extensive data on food consumpti on patterns are compiled by the USDA under the National Health and Nutrition Survey/What We Eat in America (NHANES/WWEIA) and are used in pesticide risk assessments for all regist ered food uses of a pesticide. These data are analyzed and categorized by subgroups based on age and ethnic group. Additionally, OPP is able to assess dietary exposure to smaller, sp ecialized subgroups and e xposure assessments are performed when conditions or circumstances warrant. Whenever appropriate, non-dietary exposures based on home use of pesticide products and associated risks for adult applicators and for toddlers, youths, and adults entering or playing on treated areas post-application are evaluated. Further considerations are currently in development as OPP has committed resources and expertise to the development of specialized software and mode ls that consider exposure to bystanders and farm workers as well as lifesty le and traditional dietary patterns among specific subgroups.Bensulide Human Health Risk Assessment DP No. D428598

Page 14 of 97 4.0 Hazard Characterization and Dose-Response Assessment

Bensulide is a member of the or ganophosphate class of pesticides. Like other OPs, the initiating event in the adverse outcome pathway (AOP), al so often called the mode of action (MOA), for bensulide involves inhibition of the enzyme acetylcholinesterase via phosphorylation of the serine residue at the active site of the enzy me. This inhibition l eads to accumulation of acetylcholine and ultimately to neurotoxicity in the central and/or peripheral nervous system (see Figure 1). For bensulide, acetylcholinesterase in hibition (ChEI) is the most sensitive endpoint in the toxicology database in multiple species, durations, lifestages, and routes. ChEI is the focus of this hazard characterization; the av ailability of reliable ChEI dose -response data is one of the key determinants in evaluating the toxicology database.

Figure 1. Adverse outcome pathway for OPs

4.1 Toxicology Studies Available for Analysis

The database is considered complete for risk assessment, with the exception of a repeat dose inhalation toxicity study and a bensulide oxon CCA (data gaps). The Health Effect Divisions (HED’s) Hazard Science Policy Council (HASPOC) determined, based on a weight of evidence (WOE) approach that a subchroni c inhalation toxicity study is required for bensulide due to unacceptable inhalation risk estimates using th e current POD from an oral study (Leshin, 2015, TXR # 0057280). The HASPOC also determined th at the immunotoxicity study is not required for bensulide (Van Alstine, 2013; TXR # 0056738), as well as the 6-month ocular toxicity study in the dog, and developmental and subchroni c neurotoxicity studi es (Leshin, 2015, TXR # 0057280). Although oxon CCA data are not available fo r bensulide, EPA plans to move forward

with the bensulide human health risk assessm ent without toxicity da ta for bensulide’s oxon degradate. In lieu of bensulide-specific oxon CCA data, EPA will use an oxon toxicity adjustment factor of 50X in its calculations (see section 4.6.2 for the rationale for 50X). This

value considers the data derive d toxicity adjustment factor (TAF) EPA has identified among oxon metabolites for other organophosphates, with an additional margin of safety included due to the uncertainty in extrapolat ing oxon potency data across ch emicals. Toxicology data requirements and confirmation that bensulide meets these requirement s are presented in Appendix A.1. The toxicology database incl udes the following toxicity studies:

 Subchronic oral in rat, mouse, and dog

 21-day dermal in rat (two studies)

 Developmental in rat and rabbit

 2-generation reproduction in rat

 Chronic oral in dog, mouse (carcinogenicit y), and rat (combined chronic toxicity/ carcinogenicity) Target

Tissue Dose Phosphorylation

of the active site
of AChE Neurotoxicity Accumulation of

acetylcholineBensulide Human Health Risk Assessment DP No. D428598

Page 15 of 97  Acute neurotoxicity in rat; delayed ne urotoxicity study in hen, comparative cholinesterase assay (CCA) study (gestational, repeated-dose, and acute) in parent but not

oxon

 Other studies, such as mutagenicity battery, acute 6-pac k, and metabolism study

4.2 Absorption, Distribution, Metab olism, and Elimination (ADME)

Bensulide is a phosphorothioate an d needs to be bioactivated in vivo to its oxygen analog to exert its toxic action (see chemical structure in Tabl e 3.1.1). Seven days afte r a single oral dose of

14 C-bensulide to rats, radioactiv ity was excreted primarily in the urine in males (70.2-78.6% of administered dose [AD]) and females (75.2-88.4% AD), with the rest being in the feces (13.6- 22.4% AD in males, 8.3-19.6% AD in females). Fema les excreted the radio activity faster than males: the females' excretion was almost comp lete 48 hours after dosing, whereas the males had excreted about 65-70% of the radioactivity at that time. Biliary excretion is minimal. Seven days after administration, the highest c oncentration of radioa ctivity in selected tissues in the ADME study was found in whole blood, associated with the cellular co mponent. Whole body autoradiography showed a much higher level of radioactivity remaining in males after 24 hours than in females. Four metabolites were identified. One was the primary urinary metabolite and

the other identified metabolites were found in the feces. The proposed formation of two metabolites involved the cleavage of the PO 2 [CH(CH 3 ) 2 ] 2 moiety of bensulide, followed by methylation and oxidation of the sulphur atom . Conjugation with glyc ine or carboxylation and oxidative desulphuration is proposed to lead to the other two id entified metabolites.

4.2.1 Dermal Absorption

Although there are no dermal absorption studies submitted for bensulide, a dermal absorption factor is needed for risk assessment, since the route-specific dermal toxicity study could not be modeled due to a lack of dose response, and an oral endpoint was selected for the dermal exposure assessment. A dermal absorption valu e of 10% was estimated for dermal risk

assessment. This value was derived from a co mparison of the effects observed in the oral developmental toxicity (95 mg/kg/day based upon tremors and decreased body weight) and 21- day dermal toxicity studies (1000 mg/kg/day [NOAEL]) in rats.

4.3 Toxicological Effects

Bensulide is an OP with a neurotoxic AOP; neurotoxicity is the most sensitive effect in all species, routes, and lifestages a nd is being used in deriving points of departure (acute = 11 mg/kg/day; steady-state = 6 mg /kg/day). Bensulide has dose response data across multiple lifestages, durations, and routes for both RBC and brain ChEI. Many of these studies have been evaluated using benchmark dose modeling tech niques. The CCA, in particular, provided excellent dose-response data for modeling.

Bensulide requires bioactivati on to the oxon to allow ChEI; however, no data were submitted regarding the toxi city of the oxon.Bensulide Human Health Risk Assessment DP No. D428598

Page 16 of 97 The RBC AChE was more sensitive than the brain AChE to bensulide in every analysis (all studies, durations, lifestages, and routes), ex cept the adult males in the acute CCA study. The adult female was typically more sensitive th an the male, while the pup and fetus did not demonstrate sex-sensitivity.

Clinical signs of neurotoxicity can be found th roughout the database of experimental toxicity studies at doses much higher ( ≥ 95 mg/kg/day) than those doses causing ChEI. Some of the clinical signs included diarrhea, flaccid abdominal and/or body tone, pinpoint pupils, salivation, lacrimation, decreased respira tion, hypothermia, tremors, hypoactivity, dehydration, fur staining, decreased arousal and locomotor activity. No e ffects were noted on neuropathology; however,

bensulide did not induce acute dela yed neurotoxicity in the hen.

Although the nervous system was the principal target , the liver was also a ffected. Liver toxicity (increased organ weight, incr eased serum ALT, hypertrophy, liv er enlargement, liver lipid deposits, pigmentation, and/or vacuolation) was ofte n noted in rat, mouse, and dog at doses of 30 mg/kg/day or greater.

Increased sensitivity was not evident in the developmental studies. No developmental toxicity was observed in the rat at dose levels resulting in maternal toxicity (95 mg/kg/day resulted in tremors and ChEI). Likewise, no developmental toxi city was observed in th e rabbit at dose levels resulting in maternal toxicity (80 mg/kg/day resulted in decreased body weights and body weight loss). In the rat 2-generation repr oductive toxicity study, systemic t oxicity was noted in offspring (93 mg/kg/day resulted in decreased F2 pup survival ) at a lower dose than in adults (no systemic toxicity observed). However, Ch EI provides the most sensitiv e endpoint for bensulide, and although ChEI was not measured in pups in the reproduction study, ChEI in adults (occurring at mid- and/or high dose) in this study is protective for the decr eased F2 pup survival (as the decrease in survival was noted only at the high do se). In the comparative cholinesterase assays, the ChEI observed in the PND 11 pup was genera lly greater than the inhibition observed in the adult in both the acute and repeated phases of the CCA study. In the gestational CCA, the fetus was not more sensitive than the dam. The pregna nt female in the gestational CCA was not more sensitive than the non-pregnant fe male in the repeated dose CCA.

Bensulide is classified as “not likely to be carcinogenic in humans” based on the absence of

treatment-related tumors in two adequate rodent carcinogeni city studies. There is no mutagenicity concern for bensulide.

The acute (lethal) oral toxicity of bensulide is Toxicity Category II. The acute lethal toxicity is low for other routes, Toxicity Category III or IV for dermal and inhalation toxicity; and dermal and eye irritation. It is not a dermal sensitizer.

More detail concerning the charac terization and quantifica tion of the toxic effe cts of bensulide is provided in Appendix A.2. OPP’s c holinesterase (ChE) policy and use of BMD modeling is also

described. A table of the benchmark modeling results is provided in Appendix A.2 (Tables A.2.1 and A.2.2). A toxicity profile table can be found following the benchmark modeling table in Appendix A.2 (Tables A.2.3 and A.2.4). It is noted that the toxicity profile table has not beenBensulide Human Health Risk Assessment DP No. D428598

Page 17 of 97 updated to include BMD results since these can be found in th e previous tables (A.2.1 and A.2.2).

4.3.1 Critical Durations of Exposure

One of the key elements in risk assessment is the appropriate integration of temporality between the exposure and hazard assessments. One advant age of an AOP understanding is that human health risk assessments can be refined, focused on the most relevant durations of exposure. Table 4.3.1.1 provides a summary of the sel ected results from experimental toxicology studies in which

ChEI of adult female rat RBC was selected to hi ghlight the effect of duration. Data from the adult female rat RBC ChEI was presented because this sex and compartment were the most

sensitive to the effects of be nsulide and provided the most da ta which modeled successfully. Only the BMD 10 results are shown, because the central estimate is used for purposes of comparison according to the BMD guidance.

Table 4.3.1.1. Comparison of Bensulide BMD 10 Results (mg/kg/day) for RBC ChEI over Time in Adult

Female Rats

Duration of dosing Females

BMD 10 MRID#, Test

0.67 days 27.2 49433502, Acute CCA

10 days 18.7 49466201, Repeated Dose CCA

13 days 12.0 49454001, Gestational CCA

13 weeks 9.5 43919601. 13-Week Oral Tox

25 weeks 7.3 44161101, 104-Week Chronic Tox/Carc

51 weeks 4.2 44161101, 104-Week Chronic Tox/Carc

77 weeks 6.6 44161101, 104-Week Chronic Tox/Carc

103 weeks 11.7 44161101, 104-Week Chronic Tox/Carc CCA = Comparative cholinesterase assay Tox = Toxicity; Carc = Carcinogenicity

The following text provides an analysis of the temporal pattern of AC hE inhibition from acute, single dosing and repeated dosing st udies in laboratory animals fo r bensulide. This analysis provides the basis for determining which exposure durations are appropriate for assessing human

health risk.

OPs exhibit a phenomenon known as steady-state ChEI. After repeat ed dosing at the same dose level, the degree of inhibition comes into equilibrium with th e production of new, uninhibited enzyme. At this point, the amount of ChEI at a given dose remains relatively consistent across duration. In general, OPs reach steady-state within 2-3 weeks. For bensulide, the results in Table 4.3.1.1 show a pattern of steady-state reached by 13 days of exposure. As demonstrated in the table, the BMDs decrease from acute to repeat exposure, as is typically observed with OP administration. For instance, the BMD 10 in adult female rats was 27 mg/kg in the acute CCA study (oral gavage) and 19 mg/kg/day after 10 da ys. Although there was va riation, this can be expected from using different studi es, due to differences in dose selection leading to differences in the quality of modeling. In this case, the BMD 10 after 13 days (12.0 mg/kg/day) is the same asBensulide Human Health Risk Assessment DP No. D428598

Page 18 of 97 after 103 weeks (11.7 mg/kg/day). Furthermor e, considering the variation in BMD 10 values seen in the bensulide data sets, the BMD 10 after 10 days (18.7 mg/kg/day) can be considered similar to that after 13 days. Thus, in addition to the consistency across durations, the data across multiple

studies are similar. Given the results in Table 4.3.1.1, for bensu lide, single-day and steady-state durations are appropriate for human health risk assessment. As such, the endpoint selection for bensulide focuses on acute, single-d ay effects and steady-state eff ects (10 days and longer).

Although the durations of the toxicity and expos ure assessments may differ among the OPs, an exact match is not necessary and would suggest a level of precision that th e toxicity data do not support. As such, the single chemical OP assessm ents will evaluate stead y-state, instead of the typical chronic duration dietary as sessment. The steady-state point of departure is protective of any exposure duration longer than 10 days for bensulide, including chronic exposure, since

cholinesterase inhibition does not increase afte r reaching maximum inhibition or steady-state.

Although there are data at a shorter time pe riod than 21 days (i.e., 10 days), exposure assessments of 21 days and longer will be conducted for all routes of exposure (i.e., oral, dermal and inhalation) for all single chemical OP assess ments. Although the durations of the toxicity and exposure assessments may differ, an exact ma tch is not necessary and would suggest a level of precision that the toxicity data do not support. Given this , the 21-day and longer exposure assessment is scientifically supportable and also provides consistency with the OP cumulative risk assessment (OP Cumulative Risk Asse ssment (CRA); 2002, 2006) and across the single

chemical risk assessment for the OPs.

Given the results in Table 4.3.1.1 above, acute (s ingle day) and steady-state durations are appropriate for human health risk assessment. As such, the e ndpoint selection focuses on acute, single day effects and steady-state effects. For purposes of consistency with the OP cumulative risk assessment (CRA) and other OPs, exposur e assessments of 21 days and longer will be

conducted.

4.4 Literature Review on Ne urodevelopment Effects

For the OPs, historically the Ag ency has used inhibition of AChE as the POD for human health risk assessment; at present time, this policy continues. This science policy is based on decades

of work which shows that AChE inhibition is the initial event in the pathway to acute cholinergic neurotoxicity. The use of AChE inhibition da ta for deriving PODs wa s supported by the FIFRA SAP (2008, 2012) for chlorpyrifos as the most robust source of dose-response data for extrapolating risk and is the sour ce of data for PODs for bensulide. A detailed review of the epidemiological studies used in this review can be found either in the 2014 chlorpyrifos revised

draft human health risk asse ssment ((D424485, D. Drew et al ., 12/29/2014) or in the 2015 literature review for other organophos phates (OPP/USEPA; D331251; 9/15/15).

Newer lines of research on OPs in the areas of potential AOPs, in vivo animal studies, and notably epidemiological studies in mothers and children, have raised some uncertainty about the Agency’s risk assessment approach with regard to the potential for neurodevelopmental effects in fetuses and children. Many of these studies have been the s ubject of review by the Agency over the last several years as part of efforts to develop a risk assessment for chlorpyrifosBensulide Human Health Risk Assessment DP No. D428598

Page 19 of 97 (D424485, D. Drew et al., 12/29/2014). Initially, th e Agency focused on studies from three US cohorts: 1) The Mothers and Newborn Study of North Manhattan and South Bronx performed by

the Columbia Children’s Center for Environmenta l Health (CCCEH) at Columbia University; 2) the Mt. Sinai Inner-City Toxicants, Child Grow th and Development Study or the “Mt. Sinai Child Growth and Development Study;” and 3) the Center for Health Assessment of Mothers and Children of Salinas Valley (CHAMACOS) conducte d by researchers at Univ ersity of California Berkeley. The Agency has evaluated these studies and sought external peer review (FIFRA SAP reviews in 2008 and 2012; federal panel, 2013 1 ) and concludes they are of high quality. In the three US epidemiology cohort studies, mother-inf ant pairs were recruited for the purpose of studying the potential health eff ects of environmental exposures during pregnancy on subsequent child development. Each of these cohorts evaluate d the association between prenatal chlorpyrifos and/or OP exposure (with adverse neurodevelo pmental outcomes in children through age 7 years. For the 2014 chlorpyrifos revised human health risk assessment (D424485, D. Drew et al., 12/29/2014), EPA included epid emiologic research results from these three US prospective birth cohort studies but primarily focused on the results of CCCEH since this cohort has published studies on the associ ation between cord blood leve ls of chlorpyrifos and neurodevelopmental outcomes. The Agency retained the FQPA 10X Safety Factor (SF) in the 2014 chlorpyrifos revised risk as sessment, in large part, based on the findings of these studies.

In the 2015 updated literature re view (OPP/USEPA; D331251; 9/15/ 15), the Agency conducted a systematic review expanding the scope of the 2012/2014 review focused on US cohort studies with particular emphasis on chlorpyrifos. Th e expanded 2015 review incl udes consideration of the epidemiological data on any OP pesticide, study designs beyond prospec tive cohort studies,

and non-U.S. based studies. The updated literature revi ew identified seven studies which were relevant (Bouchard et al., 2010; Fortenberry et al., 2014; Furlong et al., 2014; Guodong et al., 2012; Oulhote and Bouchard, 2013; Zhang et al., 2014; Shelton et al., 2014). These seven

studies have been evaluated in context w ith studies from the 2012/2014 review (D424485, D. Drew et al., 12/29/2014). Only a br ief summary is provided below.

The OP exposure being assessed in many of these st udies used concentrations of urinary dialkyl phosphate metabolites (DAPs) as the urinary biom arker. Total DAPs is a non-specific measure of OP exposure and is the sum of six separa te molecules - three dimethyl alkylphosphate (DMAP) molecules of DMP, DMTP, DMDTP, and three diethyl alkylphosphate (DEAP) molecules of DEP, DETP, and DEDTP. Each metabolite is a breakdown product from multiple OPs (Table 4.4.-1; CDC, 2008) 2 . Specifically, DMP, DMTP, and DMDTP are associated with 18, 13, and 5 OPs, whereas DEP, DETP, and DEDTP are associated with 10, 10, and 4 OPs, respectively. Thus, using urinary DAPs alone as an exposure measure, it is not possible to separate the exposure and associated effects for single, specific OPs.

1 http://www.regulations.gov/#!document Detail;D=EPA-HQ-OPP-2008-0850-0170

2 http://www.cdc.gov/nchs/data/nhanes/nhanes _03_04/l26opd_c_met_organo phosphorus_pesticides.pdfBensulide Human Health Risk Assessment DP No. D428598

Page 20 of 97 Table 4.4.1.CDC Table of organophosphate pesticides and their dialkyl phosphate metabolites (2008).

Pesticide DMP DMTP DMDTP DEP DETP DEDTP

Azinphos methyl X X X
Chlorethoxyphos X X Chlorpyrifos X X Chlorpyrifos methyl X X Coumaphos X X Dichlorvos (DDVP) X

Diazinon X X Dicrotophos X

Dimethoate X X X

Disulfoton X X X

Ethion X X X

Fenitrothion X X

Fenthion X X Isazaphos-methyl X X

Malathion X X X

Methidathion X X X Methyl parathion X X

Naled X Oxydemeton-methyl X X

Parathion X X

Phorate X X X

Phosmet X X X Pirimiphos-methyl X X Sulfotepp X X Temephos X X

Terbufos X X X Tetrachlorviphos X

Trichlorfon X
DMP = dimethylphosphate; DEP = diethylphosphate; DMTP = dimethylthiophosphate; DMDTP = dimethyldithiophosphate; DETP = diethylthiophosphate; DEDTP = diethyldithiophosphate.

For studies which measured urinary 3,5,6-trichloro-2-pyridinol ( TCPy) (e.g., Fortenberry et al., 2014; Eskenazi et al., 2007; Whyatt et al., 2009 ), this metabolite can be derived from chlorpyrifos, chlorpyrifos-methyl , and the herbicide triclopyr. TCPy is also the primary environmental degradate of chlorpyrifos, chlorp yrifos-methyl, and tricl opyr; thus exposure can be found directly on food treated with these pesticides. CCCEH studies have largely used chlorpyrifos measured in cord blood as the specific biomarker (e.g., Lovasi et al., 2010; Whyatt et al., 2004; Rauh et al., 2011). The CHARGE study (Shelton et al., 2015) did not measure biomarkers but instead used geospatial analysis to focus on the residential proximity to OP exposure using data from the California Depart ment of Pesticide Regul ation, with five OPs accounting for a total of 73% of the pesticide applied near resi dential settings (chlorpyrifos, acephate, diazinon, bensulide, and dimethoate).Bensulide Human Health Risk Assessment DP No. D428598

Page 21 of 97 Similarly, DAPs can be found directly on food fo llowing OP applications (Zhang et al., 2008; Chen et al., 2012). Specificall y, studies have shown that DAPs may form as environmental degradates from abiotic hydrolys is, photolysis, and plant metabo lism (Zhang et al., 2008; Chen et al., 2012; Racke et al., 1994). Furthermore, since these DAPs are excreted more rapidly and extensively than the parent OPs (Zhang et al., 2008; Forsberg et al., 2008), direct exposure to DAPs may lead to an overestimate of OP exposur e when using urinary DAPs as a biomarker of OP exposure. The Agency recognizes that this is a source of uncertain ty when using DAPs for assessing OP exposure and will continue to m onitor this issue in future assessments.

With respect to neurological effects near birt h, the CHAMACOS and Mt. Sinai cohorts measured neurological effects at birth, and observed a pu tative association with total DEAP, total DMAP, and total DAP exposure (Engel et al., 2007; Y oung et al., 2005). Similarly, a Chinese study (Zhang et al., 2014) reported stat istically significant associations for total DEAPs, total DMAPs, and total DAPs from prenatal OP pesticide expo sure and neonatal neurodevelopment assessed 3 days after birth. However, another cross- sectional Chinese study, Guodong et al. (2012),

observed no association with ur inary DAPs and a developmental quotient score for 23-25 month

old children.

The 3 US cohorts (CCCEH, Mt. Sinai, CHAMACOS ) each reported evidence of impaired mental and psychomotor development, albeit not consistent by age at time of testing (ranging from 6

month to 36 months across the th ree cohorts). Attentional pr oblems and ADHD were reported by three prospective cohorts [Rauh et al., 2006; Eskenazi et al., 2007; Ma rks et al., 2010; and Fortenberry et al. (2014)] inve stigators with additional support from a case control study, Bouchard et al. (2010). The exposure metric varied among these studies. Specifically, Fortenberry et al. (2014) found suggestive eviden ce of an association with TCPy and ADHD in boys, whereas statistically signi ficant associations were obser ved by Rauh et al. (2006) with chlorpyrifos exposure and ADHD. Eskenazi et al. (2007) reported associations with total DMAPs and total DAPs and ADHD; Marks et al. (2010) reported associations with total DEAP, DMAP, and total DAP exposure and ADHD. In a national cross-sectional study of Canadian children, using 2007-2009 data for children age 6- 11 years (Oulhote and Bouchard, 2013), there were no overall statistically significant asso ciations observed between child urinary DEAP, DMAP, or total DAP metabolite levels and parentally reported behavioral problems. In contrast, Bouchard et al. (2010), looking at U.S. children age 8-15 years in the 2000-2004 National Health and Nutrition Examination Survey (NHANES), observed a positive association between attention and behavior problems and total DAPs a nd DMAPs, but not DEAPs. As part of their analysis, Oulhote and Bouchard (2013) noted th at their outcome assessment for behavioral problems may not have been as sensitive as Bouc hard et al. (2010), which may in part account

for the difference in the observed results from these studies.

In addition, the three US cohorts and the CHAR GE study have reported suggestive or positive associations between OP exposure and autism sp ectrum disorders (Rauh et al., 2006; Shelton et al., 2014; Eskenazi et al., 2007; Furlong et al ., 2014). Specifically, Fu rlong et al. (2014) documented suggestive evidence of an associati on between total DEAP exposure and reciprocal social responsiveness among blacks and boys. Eske nazi et al. (2007) re ported a statistically significant association between pervasive developmental disorder (PDD) and total DAP exposure, whereas Eskenazi et al. (2010) reporte d non-significant, but suggestive, increased oddsBensulide Human Health Risk Assessment DP No. D428598

Page 22 of 97 of PDD of 2.0 (0.8 to 5.1; p=0.14). Rauh et al. (2006) documented a significant association between PDD and specifically chlorpyrifos e xposure. Both PDD and reciprocal social responsiveness are related to the autism spectrum disorder. Using a different exposure assessment method (geospatial analysis and reside ntial proximity to total OP exposure), Shelton et al. (2014) also showed stat istically significant a ssociations between to tal OP exposure and ASD. While these studies vary in the magnitude of the overall strength of association, they have consistently observed a positive association be tween OP exposure and ASD. Finally, CCCEH, Mt. Sinai, CHAMACOS have reported an inve rse relation between the respective prenatal measures of chlorpyrifos and in telligence measures at age 7 years (Rauh et al., 2011; Engel et al., 2011; Bouchard et al., 2011).

Across the epidemiology database of studies, the maternal urine, cord blood, and other (meconium) measures provide evidence that exposu re did occur to the fetus during gestation but the actual level of such exposur e during the critical window(s) of susceptib ility is not known. While significant uncertainties remain about the actual exposure levels ex perienced by mothers and infant participants in the children’s health co horts, it is unlikely that these exposures resulted in AChE inhibition. As part of the CHAMACOS study, Eskenazi et al. (2004) measured AChE activity and showed that no differences in AChE activity were observed. The biomarker data (chlorpyrifos) from the Colu mbia University studies are supported by the Agency’s dose reconstruction analysis using the PBPK-PD model (D424485, D. Drew et al., 12/29/2014). Following the recommendation of the FIFRA SAP (2012), the Agency conducted a dose reconstruction analysis of resi dential uses available prior to 2000 for pregnant women and young

children inside the home. The PBPK-PD mode l results indicate for the highest exposure considered (i.e., indoor broadcast use of a 1% chlorpyrifos form ulation) <1% RBC AChE inhibition was produced in pregna nt women. While uncertainty ex ists as to actual OP exposure at (unknown) critical windows of exposure, EP A believes it is unlikely individuals in the epidemiology studies experi enced RBC AChE inhibition.

A review of the scientific literature on poten tial modes of action/a dverse outcome pathways (MOA/AOP) 3 leading to effects on the developing brain was conducted for the 2012 FIFRA SAP meeting (USEPA, 2012) and updated for the D ecember 2014 chlorpyrifos revised risk assessment (D424485, D. Drew et al., 12/29/2014). In short, multiple biologically plausible hypotheses and pathways are being pursued by resear chers that include targ ets other than AChE inhibition, including cholinergic and non-cholinergic systems, si gnaling pathways, proteins, and others. However, no one pathway has sufficient da ta to be considered more credible than the others. The fact that there are, how ever, sparse AOP data to support the in vitro to in vivo extrapolation, or the extrapol ation from biological perturba tion to adverse consequence significantly limits their quantitative use in ri sk assessment. The SAP concurred with the Agency in 2008 and 2012 about the lack of defi nable key events in a MOA/AOP leading to developmental neurobehavioral effects. Howeve r, since the 2014 literat ure review, there are no substantive changes in the ability to define a nd quantitate steps in an MOA/AOP leading from exposure to effects on the developing brain. Published and submitted guideline DNT laboratory

animal studies have been reviewed for OPs as part of the 2012/2014 review (D424485, D. Drew

3 Mode of action (MOA) and adverse outcome pathways (AOPs) describe a set of measureable key events that make up the biological processes leading to an adverse outcome and the causal linkages between such events.Bensulide Human Health Risk Assessment DP No. D428598

Page 23 of 97 et al., 12/29/2014) and the updated 2015 re view (OPP/USEPA; D331251; 9/15/15).

Neurobehavioral alterations in la boratory animals were often re ported, albeit at AChE inhibiting doses, but there was generally a lack of consiste ncy in terms of pattern, timing, or dose-response for these effects, and a number of studies were of lower quality. However, this information does provide evidence of l ong-lasting neurodevelopmental disord ers in rats and mice following gestational exposure.

At this time, a MOA(s)/AOP(s) has/have not been established for neurodevelopmental outcomes. This growing body of literature does demonstrate, however, that OPs are biologically active on a number of processes that affect the developi ng brain. Moreover, there is a large body of in vivo laboratory studies which show l ong-term behavioral effects from early life exposure, albeit at

doses which cause AChE inhibition. EPA consid ers the results of the toxicological studies relevant to the human populat ion, as qualitatively supported by the results of epidemiology studies. The Agency acknowledges th e lack of established MOA/AOP pathway and uncertainties associated with the lack of ability to make strong causal linkages and unknown window(s) of susceptibility. These uncertainties do not underm ine or reduce the confidence in the findings of the epidemiology studies. The epidemiol ogy studies reviewed in the 2012/2014 and 2015 literature reviews represen t different investigators, locations , points in time, exposure assessment procedures, and outcome measurements. Despite all these differences in study design, with the exception of two negative studies in the 2015 li terature review (Guodong et al., 2012; Oulhote and Bouchard, 2013), authors have identified a ssociations with neurodevelopmental outcomes associated with OP exposure across four cohorts and twelve study citations. Specifically, there is evidence of delays in mental development in infants (24-36 months), attention problems and autism spectrum disorder in early childhood, and intelligence decrements in school age children who were exposed to OPs during gestation. Investig ators reported strong m easures of statistical association across several of these evaluations (odds ratios 2-4 fold increased in some instances), and observed evidence of exposures-r esponse trends in some instances, e.g. , intelligence

measures.

As section 408(b)(2)(C) of the FFDCA instructs EPA, in ma king its “reasonable certainty of no harm” finding, that in “the case of threshold e ffects, an additional tenfold margin of safety for the pesticide chemical residue and other sources of exposure shall be applied for infants and children to take into account potential pre- and postnatal toxicity and comple teness of data with respect to exposure and toxicity to infants and children.” Section 408 (b)(2)(C) furt her states that “the Administrator may use a different margin of safe ty for the pesticide chem ical residue only if, on the basis of reliable data, such margin will be safe for infants and children.” Given the totality of the evidence, there is suffici ent uncertainty in the human dose-respons e relationship for neurodevelopmental effects which prevents the Agency from reduc ing or removing the statutory 10X FQPA Safety Factor. For the bensulide DRA, a value of 10X has been applied. Similarly, a database uncertainty factor of 10X will be retained for occupational risk assessments. The Agency will continue to evaluate the ep idemiology studies and pursue approaches for quantitative or semi-quantitativ e comparisons between doses whic h elicit AChE inhibition and those which are associated with neurodevelopmen tal outcomes prior to a revised human health

risk assessment.Bensulide Human Health Risk Assessment DP No. D428598

Page 24 of 97 4.5 Safety Factor for Infants and Children (FQPA SF)

As noted above, the lack of an established neurodevelopmental MOA/AOP makes quantitative use of the epidemiology studies in risk assessm ent challenging, particularly with respect to determining dose-response, critical duration of exposure, and window(s) of susceptibility. However, exposure levels in the range measured in the epidemiology studies are likely low enough that they are unlikely to result in AChE inhibition. Epidemiol ogy studies consistently identified associations with neurodevelopmental outcomes associated with OP exposure such as delays in mental development in infants (24-36 months), attention problems and autism spectrum disorder in early childhood, and in telligence decrements in school age children. Therefore, there is a need to protect children from exposures that may cause these effects; this need prevents the Agency from reducing or removing th e statutory FQPA Safety Factor. Thus, the FQPA 10X Safety Factor will be retained for bensulide for the population subgroups that include infants, children, youths, and women of childbearing age for all exposure scenarios.

A database uncertainty factor of 30x will be applied to inhalation risk assessment only, to incorporate the uncertainty in the human dose-response relati onship for neurodevelopmental

effects and for the absence of inhalation data.

4.5.1 Completeness of the Toxicology Database

The database of toxicology studies for bensulid e is complete, except for the requirement of a repeat dose inhalation toxicity study. Available be nsulide studies include developmental toxicity studies in rats and rabbits, a re productive toxicity study in rats, an acute neurotoxicity study in rats, and a CCA study in rats [acute (young adu lt and PND 11 pups)), repeated dose (young adult and PND 11 pups), and gestational (fetus and da m)]. A CCA study for the oxon is not available, and exposure to the oxon is considered to be 50 X as toxic as exposure to the parent in the

absence of this data.

4.5.2 Evidence of Neurotoxicity

Bensulide is an OP with a neurotoxic AOP; neurotoxicity is the most sensitive effect in all species, routes, and lifestages and is being used to derive PODs fo r risk assessment. Therefore, the risk assessment is protective of potential ne urotoxicity for every life stage and route of

exposure.

4.5.3 Evidence of Sensitivity/Susceptibility in the Developing or Young Animal

Sensitivity was not evident in the developmen tal studies. No developmental toxicity was

observed in the rat at dose leve ls resulting in maternal toxicity (tremors and decreased AChE). Likewise, no developmental toxi city was observed in the rabbit at dose levels resulting in maternal toxicity (decreased body weights and body weight loss). In the rat 2-generation reproductive toxicity study, systemic toxicity was noted in offspring (decreased F2 pup survival at the high dose), while no systemic toxicity wa s noted in adults. However, ChEI provides the most sensitive endpoint for bensulide, and alth ough ChEI was not measured in pups, ChEI in adults in this study (observed at mid and/or high dose) is protective (6.7-fold more sensitive) forBensulide Human Health Risk Assessment DP No. D428598

Page 25 of 97 the decreased F2 pup survival. The PND 11 pup was generally more sensitiv e than the adult in the acute and repeated dose CCA. The CCA study did not demonstrate the fetus to be more sensitive than the dam. Endpoints were chos en to be protective of all lifestages.

As discussed in Section 4.4, there is uncertainty in the human dose-response relationship for neurodevelopmental effects and th is warrants retention of the FQPA Safety Factor for the population subgroups that include infants, child ren, youths, and women of childbearing age for all exposure scenarios.

4.5.4 Residual Uncertainty in the Exposure Database

There are no residual uncer tainties with regard to the exposur e databases. The acute and steadystate dietary assessment incor porated PDP monitoring data fo r bensulide and its oxon (when available), anticipated residues, default DEEM pr ocessing factors, and percent crop treated (CT). A TAF of 50x was applied to residues of th e oxygen analog in food commodities and drinking water, as well as turf transferab le residue data used in the resi dential assessment. Although data

were used to refine the acute and steady-state dietar y exposure assessments, the assessments are not expected to underestimate di etary (food and water) exposures. The residential handler and post-application exposure assessments are base d upon the residential SOPs. The residential SOPs are based upon reasonable worst-case assump tions and are not expect ed to underestimate risk. These assessments of exposure are not lik ely to underestimate the resulting estimates of risk from exposure to bensulide.

4.6 Toxicity Endpoint and Point of Departure Selections

4.6.1 Dose-Response Assessment

Table 4.6.4.1 summarizes the bensulid e toxicity endpoints and PODs selected from an evaluation of the database. This endpoint selection was ba sed on a weight of the evidence evaluation using the following considerations:

 Relative sensitivity of th e brain and RBC compartments : The RBC AChE was more

sensitive than the brain AChE to bensulide in every analysis (all studies, durations, lifestages, and routes), excep t the adult males in the acute CCA study. As such, OPP has relied upon the RBC data in POD derivation.

 Potentially susceptible populations (f etuses, juveniles, pr egnancy, or sex ): The available AChE data across multiple lifestages (adults, pregnant adults, fetuses, juveniles) show

that the PND 11 pups were generally more sensitive th an the adult 1.5-4.5 -fold. In the gestational CCA, the fetus was not more sensitive than the dam. The pregnant female in the gestational CCA is not more sensitive than the non-pregnant female in the repeated dose CCA. The adult female was typically more sensitive than the adult male, while the pup and fetus did not demonstrate se x-sensitivity. See Appendix A.5.

 Route of exposure: It is preferred to match, to the de gree possible, the route of exposure in the toxicity study with that of the exposure scenario(s) of interest. In the case of bensulide, BMD modeling data are only availabl e for the oral route. The data from the dermal study were not amenable to modeling (no apparent dose response); however, theBensulide Human Health Risk Assessment DP No. D428598

Page 26 of 97 dermal absorption is low (DAF = 10%). An inhalation study is not available but is required.

 Duration of exposure: It is preferred to match, to the degree possible, the duration of a toxicity study with that of the exposure dur ation of interest. There are single-day and steady-state oral studies avai lable. Steady-state dermal st udies are available, but no inhalation study is available.

 Consistency across studies: In cases where multiple datasets are available for a single duration, it is important to evaluate the extent to which data are consistent (or not) across studies. Considering the presence of sensitive populations, that different labs conducted the studies across several years, the bensulide database demonstrated consistent ChEI and effects. In particular, the study protocol and performance of the CCA enable great

confidence in the resu lts of this study.

Descriptions of the primary toxici ty studies used for selecting t oxicity endpoints and points of departure for various exposure scenarios are pr esented in Appendix 3 of this document. Summary tables of BMD analyses can be found in Appendix 2, and the technical details of the analysis can be found in the BMD memo (Bever, 2015, TXR # 0057236).

Consistent with risk assessments for ot her AChE-inhibiting compounds, OPP has used a benchmark response (BMR) level of 10% and has thus calculated BMD 10 s and BMDL 10 s (see Appendix A.2. for summary of OPP’s ChE policy). The BMD 10 is the estimated dose where ChE is inhibited by 10% compar ed to background. The BMDL 10 is the lower confidence bound

on the BMD 10 . As a matter of science policy, the Agency uses the BMDL, not the BMD, for use as the POD (USEPA, 2012). All BMD/BMDL modeling was completed using USEPA BMD Software, version 2.4; an expone ntial model or Hill model was used to fit the data.

Acute Dietary Endpoint (All Populations) A POD for the acute dietary (all populations) exposure scenario was derived from the results of a high-quality, well-conducted acute CCA rat study (MRID 49433502). A BMDL 10 of 11 mg/kg

was selected and was associated with RBC Ch E inhibition in female pups (PND 11). The corresponding BMD 10 was 16 mg/kg. RBC cholinesterase inhibition was selected as the endpoint for the POD, since BMD 10 values were lower than t hose for brain cholinesterase

inhibition. Data from the PND 11 pups are appropriate for acut e POD derivation, since effects were observed after a single exposure and the endpoi nt is the most sensitive adverse response in all populations (infant and child ren, females 13+, and adults).

An uncertainty factor of 1000X (10X to acc ount for interspecies extrapolation, 10X for intraspecies variation, and 10X fo r FQPA safety/ database uncertai nty factor due to uncertainty in the human dose-response relationship for ne urodevelopmental effects (see Section 4.4)) is applied to the BMDL 10 to obtain an aPAD of 0.011 mg/kg/ day for exposure scenarios with infants, children, youths, and women of childbe aring age. The only population subgroup for which the FQPA SF is not retained is adults 50-99; therefore, th e aPAD for this population subgroup is 0.11 mg/kg/day.Bensulide Human Health Risk Assessment DP No. D428598

Page 27 of 97 Steady-State Dietary En dpoint (All Populations) A POD for the steady-state dietary (all population s) exposure scenario was derived from the repeated-dose response observed in a CCA rat study (MRID 49466201). A BMDL 10 of 6 mg/kg/day was selected and was associated with RBC ChE inhibition in male pups (PND 11 initially). The corresponding BMD 10 was 8 mg/kg/day. RBC cholin esterase inhibition was selected as the endpoint for the POD, since BMD 10 values were lower than those for brain

cholinesterase inhibition. Of th e best modeled data sets, data from the PND 11 pups provided the most sensitive adverse response of all populations (infant and children, females 13+, and adults). Discussion of the steady-state POD is provided in Section 4. 3.1. The modeling of the CCA study allowed for a much greater confidence in th e accuracy of the resulting estimated BMDL 10

. Overall, the CCA study provided the best source of data to establis h the steady-state value due to more optimal selection of doses, the number of dose groups (6), sampling at the time of peak effect from a gavage study, several lifestages (adult, PND 11 pups, pregnant dams, fetuses), acute and repeat exposure periods , and the quality of BMD modeling lending confidence to the results. Furthermore, the CCA study allowed th e evaluation of the most sensitive life stage (PND 11 pups). The combination of best fit mo deling and most protective value occurred for ChE inhibition in the PND 11 male RBC following 10 daily doses (6 mg/kg/day, repeated dose CCA study). The BMD 10 of 8 mg/kg/day from this study fits w ithin the range of that observed at longer durations in the chronic t oxicity/ carcinogenicity study.

The endpoint and POD are protective of all ot her effects observed in the database. An uncertainty factor of 1000X (10X to account for interspecies extrapolatio n, 10X for intraspecies variation, and 10X for FQPA safety / database uncertainty factor due to uncertainty in the human dose-response relationship for neurodevelopmental effects (see Section 4.4 )) is applied to the

BMDL 10 to obtain a ssPAD of 0.006 mg/kg/day for al l exposure scenarios, except adults 50-99. Excluding the FQPA SF for adults 50 -99, the ssPAD is 0.06 mg/kg/day.

Incidental Oral Endpoint/ Steady-State A POD of 6 mg/kg/day was selected from the re peat dose CCA study in rats, based on the same rationale provided above for the steady-state di etary exposures. A total uncertainty factor of 1000X is appropriate for incidental oral exposures (10X for inte rspecies extrapolation, 10X for intraspecies variation, and 10X for FQPA SF due to uncertain ty in the human dose-response relationship for neurodevelopmental effects (s ee Section 4.4)) allowi ng a Level of Concern (LOC) of 1000X.

Dermal Endpoints/ Steady-State A POD of 6 mg/kg/day was selected from the re peat dose CCA study in rats, based on the same rationale provided above for the steady-state dietary exposures. The POD was adjusted based on a 10% dermal absorption factor to 60 mg/kg/day. A total unc ertainty factor of 1000X is appropriate for dermal exposures (10X for inte rspecies extrapolation, 10X for intraspecies variation, and a 10X FQPA SF for residential assessments or a da tabase uncertainty factor in occupational assessments due to uncertainty in the human dose-response relationship for neurodevelopmental effects (see Sect ion 4.4)), allowing a LOC of 1000X.

The ChEI data from the dermal toxicity study wo uld not model due to a lack in dose response. The dermal toxicity study NOAEL fr om MRIDs 44801101 and 44809401 is 50 mg/kg/day,Bensulide Human Health Risk Assessment DP No. D428598

Page 28 of 97 which approximates the selected POD of 6 mg/ kg/day with the DAF of 10% (i.e. 60 mg/kg/day adjusted dose). The LOAEL was 500 mg/kg/day ba sed on brain ChEI. Due to dose spread issues related to the NOAEL approach and the quality of the BMD analysis from the CCA study, the CCA study is a more appropriate selection than the dermal study. Since plasma and brain ChEI was observed at 500 mg/kg/day, it would be expect ed that RBC inhibition be observed as well. Therefore, instead of relying on brain ChEI for only the dermal route of exposure, the RBC AChE data from the CCA study can be aggregat ed with the dermal and inhalation routes.

Inhalation Endpoints/ Steady-State A POD of 6 mg/kg/day was selected from the re peat oral dose CCA study in rats, based on the same rationale provided above fo r the steady-state dietary exposur es. A route-specific inhalation study is unavailable. Toxicity throu gh the inhalation route is consider ed to be similar to that of the oral route. The total uncertainty factor of 3000X was applied (10X for interspecies extrapolation, 10X for intraspecies variation, and 30X database unc ertainty factor incorporating uncertainty in the human dose-response relations hip for neurodevelopmental effects (see Section 4.4) and because there is an unfulfilled inhalatio n study requirement for bensulide), resulting in a

LOC of 3000X.

4.6.2 Oxon Toxicity Adjustment Factor

In the 2006 updated OP cumulative risk assessm ent (CRA), the Agency characterized the potential impacts of the convers ion of OP pesticides to oxon transformation products during standard drinking water treatment processes. Fo r those OP pesticides that could potentially transform into more toxic oxons, the Agency assu med a complete transformation as a result of drinking water treatment. Based on limited data (documented in the 2002 OP CRA), the Agency assumed that the oxons would persist for a suffi cient time to travel through the distribution

system.

The Agency used submitted data to characterize the relative toxicity differences between the oxon and the parent for some of the OP pes ticides; information fr om published literature was also

available to inform relative potency for a few OP Pesticides 4 . For those OP pesticides without sufficient oxon data, the Agency initially used upper bound oxon ad justment factors of 10X and 100X for estimating potential oxon potency. The 100X was used considering the highest relative toxicity difference observed (61X) for malath ion/malaoxon, based on the data available at the time. However, since then, acute and repeat dose CCA studies have been submitted for both

malathion and malaoxon. The new data allow a dire ct comparison of relative toxicity for the two chemicals and therefore, reduces uncertainty; an oxon adjustment factor of 22X was determined based on these data. As a result, a 50X oxon adjust ment factor has been used for the OP draft risk assessments for registra tion review to estimate poten tial oxon potency. The 50X accounts for the highest oxon adjustment fact or of 22X with an additional safety margin to protect for potential oxon toxicity for chemicals without oxon data. The adjustment factors were applied to residues for risk assessment of all exposur e durations, routes, and scenarios.

4 Chambers JE, Carr RL. 1993. “Inhibition patterns of brain acetylcholinesterase and hepatic and plasma aliesterases following exposures to three phosphorothionate insecticides and their oxons in rats.” Fundamental and Applied Toxicology. Jul;21(1):111_9.Bensulide Human Health Risk Assessment DP No. D428598

Page 29 of 97 OP PESTICIDE OXON ADJUSTMENT FACTOR Azinphos-Methyl No data

Bensulide No data Chlorethoxyfos No data Chlorypyrifos 11.9X (acute); 18X (repeated): RBC Coumaphos No data Diazinon 12.1X (acute); 9.0X (repeated):RBC Dimethoate 8 X (acute); 3X (repeated): Brain

Disulfoton No data Malathion 22X (acute); 22X (repeated): RBC

Methidathion No data Methyl Parathion <10X (Chambers and Carr, 1993) * Phostebuprim No data Propetamphos No data Temephos No data

Oxon toxicity adjustment factors are based on a comparison of the most sensitive compartment (i.e., RBC or brain) determined

for the chemical.

4.6.3 Recommendation for Combining Routes of Exposures for Risk Assessment

When there are potential occupational and resi dential exposures to a pesticide, the risk assessment must address exposures from three ma jor sources (oral, dermal, and inhalation) and determine whether the individual exposures can be combined if they have the same toxicological effects. PODs for the incidental oral, dermal, and inhalation routes ar e all derived from RBC AChE inhibition. As a result, exposure fr om all routes can be combined.

4.6.4 Cancer Classification and Ri sk Assessment Recommendation

Bensulide is classified as a “Group E Chemical – evidence of non-carcino genicity for humans”

based on lack of evidence for carci nogenicity in rats and mice. Th ere is no mutagenicity concern

for bensulide.Bensulide Human Health Risk Assessment DP No. D428598

Page 30 of 97 4.6.5 Summary of Points of Departure and T oxicity Endpoints Used in Human Risk

Assessment

Table 4.6.5.1 Summary of Toxicological Doses and Endpoints and Points of Departure for Bensulide in Dietary and Non-Occupational Human Health Risk Assessments a

Exposure

Scenario Point of Departure (mg/kg/day) Uncertainty/FQPA

Factors RFD, PAD, & LOC

for Risk Assessment Study and Toxicological

Effects

Acute Dietary

(All Populations Except Adults 50-99 Years) BMDL 10 = 11 mg/kg UF A = 10x

UF H = 10x FQPA SF = 10x Acute RfD = 0.11 mg/kg

aPAD = 0.011 mg/kg Acute CCA Study (MRID 49433502) in the rat

BMD 10 = 16 mg/kg

Inhibition of RBC ChE in female pups (PND 11)

Acute Dietary

(Adults 50-99 Years) BMDL 10 = 11 mg/kg UF A = 10x

UF H = 10x FQPA SF = 1x Acute RfD = aPAD = 0.11 mg/kg Acute CCA Study (MRID 49433502) in the rat

BMD 10 = 16 mg/kg

Inhibition of RBC ChE in female pups (PND 11)

Steady-State Dietary

(All Populations Except Adults 50-99 Years) BMDL 10 = 6 mg/kg/day UF A = 10x

UF H = 10x FQPA SF = 10x ssRfD = 0.06 mg/kg/day

ssPAD = 0.006 mg/kg/day Repeated-Dose CCA Study (MRID 49466201) in the rat

BMD 10 = 8 mg/kg/day

Inhibition of RBC ChE in male pups (PND 11 initially)

Steady-State Dietary

(Adults 50-99 Years) BMDL 10 = 6 mg/kg/day UF A = 10x

UF H = 10x FQPA SF = 1x ssRfD = ssPAD = 0.06 mg/kg/day Repeated-Dose CCA Study (MRID 49466201) in the rat

BMD 10 = 8 mg/kg/day

Inhibition of RBC ChE in male pups (PND 11 initially)

Incidental

Oral Steady-State BMDL 10 = 6 mg/kg/day UF A = 10x

UF H = 10x FQPA SF = 10x Residential LOC for

MOE = 1000x Repeated-Dose CCA Study (MRID 49466201) in the rat

BMD 10 = 8 mg/kg/day

Inhibition of RBC ChE in male pups (PND 11 initially)

Dermal Steady-State BMDL 10 = 6 mg/kg/day UF A = 10x

UF H = 10x FQPA SF = 10x

DAF = 10% Residential LOC for

MOE = 1000x Repeated-Dose CCA Study (MRID 49466201) in the rat

BMD 10 = 8 mg/kg/day

Inhibition of RBC ChE in male pups (PND 11 initially)Bensulide Human Health Risk Assessment DP No. D428598

Page 31 of 97 Table 4.6.5.1 Summary of Toxicological Doses and Endpoints and Points of Departure for Bensulide in Dietary and Non-Occupational Human Health Risk Assessments a

Exposure

Scenario Point of Departure (mg/kg/day) Uncertainty/FQPA

Factors RFD, PAD, & LOC

for Risk Assessment Study and Toxicological

Effects

Inhalation Steady-State BMDL 10 = 6 mg/kg/day UF A = 10x

UF H = 10x FQPA SF = 30x b Residential LOC for

MOE = 3000x Repeated-Dose CCA Study (MRID 49466201) in the rat

BMD 10 = 8 mg/kg/day

Inhibition of RBC ChE in male pups (PND 11 initially)

Cancer (oral, dermal, inhalation) Classification: Group E chemical; Evidence of Non-Carcinogenicity in Humans

a Point of Departure (POD) = A data point or an estimated point that is derived from observed dose-response data and used to mark the beginning of extrapolation to dete rmine risk associated with lo wer environmentally relevant human exposures. BMDL = lower limit of the bench mark dose. NOAEL = no observed adverse effect level.

LOAEL = lowest observed adverse effect level. UF = uncertainty factor. UF A = extrapolation from animal to human (interspecies). UF H = potential variation in sensitivity among members of the human population (intraspecies). SF = Safety Factor. PA D = population adjusted dose (a = acut e, ss = steady-state or maximal acetyl

cholinesterase inhibition which occurs around 2-3 week s for most OPs and is a specific exposure assessment conducted for OPs, instead of the traditional short, inte rmediate, or chronic assessments. The SS assessment is protective of longer durations of exposure, including chronic). RfD = reference dose. MOE = margin of exposure. LOC = level of concern. FQPA = Food Quality Protection Act

b This uncertainty factor incorporates uncertainty in the human dose-response relationship for neurodevelop-mental effects (see Section 4.4) and because there is an unfulfilled inha lation study requirem ent for bensulide

Table 4.6.5.2 Summary of Toxicological Doses and Endpoints for Bensulide for Use in Occupational Human

Health Risk Assessments a

Exposure/

Scenario Point of Departure Uncertainty/ FQPA

Factors LOC for Risk

Assessment Study and Toxicological Effects

Dermal Steady-State BMDL 10 = 6 mg/kg/day UF A = 10x

UF H = 10x

UF DB = 10x

DAF = 10% Occupational

LOC for MOE =

1000x Repeated-Dose CCA Study (MRID 49466201) in the rat

BMD 10 = 8 mg/kg/day

Inhibition of RBC ChE in male pups (PND 11 initially)

Inhalation Steady-State BMDL 10 = 6 mg/kg/day UF A = 10x

UF H = 10x

UF DB = 30x Occupational

LOC for MOE =

3000x Repeated-Dose CCA Study (MRID 49466201) in the rat

BMD 10 = 8 mg/kg/day

Inhibition of RBC ChE in male pups (PND 11 initially)

Cancer (oral, dermal, inhalation) Classification: Group E chemical – Evidence of Non-Carcinogenicity in HumansBensulide Human Health Risk Assessment DP No. D428598

Page 32 of 97 a Point of Departure (POD) = A data point or an estimated point that is derived from observed dose-response data and used to mark the beginning of extrapolation to determine risk associat ed with lower environmentally re levant human exposures. BMDL

= lower limit of the bench mark dose. NOAEL = no observed advers e effect level. LOAEL = lo west observed adverse effect level. UF = uncertainty factor. UF A = extrapolation from animal to human (interspecies). UF H = potential variation in sensitivity among members of the human population (intraspecies). LOC = level of concern. UF DB = database uncertainty factor

b This uncertainty factor incorporates uncer tainty in the human dose-response relations hip for neurodevelop-mental effects (see Section 4.4) and because there is an unfulfilled inhalation study requirement for bensulide Steady-State = steady-state or maximal AChE inhibition which occu rs around 2-3 weeks for most OPs and is a specific exposure

assessment conducted for OPs instead of the traditional short, intermed iate, or chronic assessments . The steady-state assessmen t is protective of longer dura tions including chronic.

4.7 Endocrine Disruption

As required by FIFRA and FFDCA, EPA reviews num erous studies to asse ss potential adverse outcomes from exposure to chemicals. Collectivel y, these studies include acute, subchronic, and

chronic durations and assess car cinogenicity, neurotoxicity, deve lopmental, reproductive, and general or systemic toxicity. These studies include endpoints which may be susceptible to endocrine influence, including effects on endocrine target organ histopat hology, organ weights, estrus cyclicity, sexual maturati on, fertility, pregnancy rates, repr oductive loss, and sex ratios in offspring. For ecological hazard assessments, EPA evaluates acute tests a nd chronic studies that assess growth, developmental, and reproductive effects in different taxonomic groups. As part of its reregistration decision for bensulide, EPA revi ewed these data and selected the most sensitive endpoints for relevant risk assessment scenarios fr om the existing hazard database. However, as required by FFDCA section 408(p), be nsulide is subject to the endoc rine screening part of the Endocrine Disruptor Screening Program (EDSP).

EPA has developed the EDSP to determine whet her certain substances (including pesticide active and other ingredients) may have an effect in humans or wildlife similar to an effect produced by a “naturally occurring estrogen, or ot her such endocrine effect s as the Administrator may designate.” The EDSP employs a two-tiered approach to making th e statutorily required

determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a chemical substance to interact with the estrog en, androgen, or thyroid (E, A, or T) hormonal systems. Chemicals that go th rough Tier 1 screening and are found to have the potential to interact with E, A, or T hormonal systems will proceed to the next stage of the EDSP, where EPA will determine which, if any, of the Tier 2 te sts are necessary based on the available data. Tier 2 testing is designed to identify any adverse endocrine -related effects caused by the

substance and establish a dose-res ponse relationship between the dos e and the E, A, or T effect.

Under FFDCA section 408(p), the Agency must screen all pesticide chemicals. Between October 2009 and February 2010, EPA issued test orders/data call-ins for the first group of 67 chemicals, which contains 58 pest icide active ingredient s and 9 inert ingredients. A second list

of chemicals identified for EDSP sc reening was published on June 14, 2013 i and includes some pesticides scheduled for registration review and chemicals found in water

. Neither of these lists

should be construed as a list of known or likely endocrine disruptors.

i See http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPPT-2009-0477-0074 for the final second list of

chemicals.Bensulide Human Health Risk Assessment DP No. D428598

Page 33 of 97 Bensulide is on List 2. List 2 represents the next set of chemicals for which EPA intends to issue

test orders/data call-ins in the near future . For further information on the status of the EDSP, the policies and procedures, th e lists of chemicals, future lists, the test guidelines and the Tier 1 screening battery, please visit our website. ii

5.0 Dietary Exposure and Risk Assessment

5.1 Residues of Concern Summary and Rationale

The nature of the residues in plants is adequate ly established based on ca rrot, lettuce and tomato

metabolism studies. The residues of concern for ri sk assessment in plants and drinking water, and tolerance enforcement in plants consis ts of bensulide and its oxon (C. Eiden, D238417, 10/06/1997). Appendix E summarizes the metabolis m data for parent bensulide and its oxygen analog.

Table 5.1. Summary of Metabolites and Degradat es to be included in the Risk Assessment and Tolerance Expression

Matrix Residues included in Risk

Assessment Residues included in Tolerance Expression

Plants Primary Crop Bensulide and its oxon Bensulide and its oxon Rotational Crop NS 1 NS 1

Livestock Ruminant NR 1 NR 1 Poultry Drinking Water Bensulide and its oxon Not Applicable

1 NS = Not specified. It was indicated that the nature of th e residue seems to be similar to that on primary crops (C. Eiden, D218575, 04/02/1997). Following the 120-day plant-back interval (PBI), residues in rotational crops do not

need to be considered for risk a ssessment and tolerance enforcement.

2 NR = Not required to support the established uses of bensulide. Livestock metabolism studies may be required if new uses are sought.

5.2 Food Residue Profile

The nature of the residues in plants is adequa tely established based on carrot, lettuce and tomato

metabolism studies. Tolerances are establishe d in the 40 CFR § 180.241 for the use of bensulide on bulb onion, leafy vegetable excep t brassica (CG 4), leafy brassi ca vegetables (CG 5), fruiting vegetable (CG 8), and cucurbit vegetables (CG 9) , and a regional registration for use on carrots. Uses on garlic and shallots are in the label as well which is covered by the tolerance for bulb onion, refer to the 40 CFR § 180.1. The establishe d tolerances are based on measurement of bensulide and its oxygen analog and range from 0.10 to 0.15 ppm. The 0.10 ppm tolerances are

based on combined levels of bensulide and its ox on at the LOQ of 0.05 ppm. However, in order to account for potential residue loss es during storage prior to analys is, the tolerance for bensulide residues on brassica vegetables (C G 5), cucurbit vegetables (CG 9) and leafy vegetables (CG 4)

ii http://www.epa.gov/endo/Bensulide Human Health Risk Assessment DP No. D428598

Page 34 of 97 is 0.15 ppm (based on twice the lim it of quantitation for bensulide per se (0.10 ppm) plus the limit of quantification for bensulide oxon (0.05 ppm)).

Metabolism studies conducted with lettuce, carrot a nd tomato show that parent bensulide was at quantifiable levels only in carrot, while the oxyg en analog was quantified in lettuce and carrot, refer to Appendix E. Levels of the oxon were higher than those of parent bensulide only in lettuce, which suggest that the oxon may predomin ate. Moreover, PDP data for lettuce (years 2010 and 2011) show that bensulide was detected in 6 of 1487 samples whereas bensulide oxon was detected in 49 of those 1487 samples. Gene rally, the concentration of the oxon in/on lettuce is higher than that of parent bensulide. PDP da ta for carrots do not show quantifiable residues of

bensulide or its oxon while data for tomato do not show residues of bensulide’s oxon.

As part of registration review, the residue chem istry database for bensulide was evaluated. The only data deficiency identified in the regi stration eligibility de cision (C. Eiden, D238417, 10/06/1997) that has not been sati sfied is additional crop field tr ials for bensulide on non-bell peppers (domestic use) and tomato (import use) . Although these data ar e not available, the dietary risk is not underestimated since the asse ssment incorporates anticipated residues for nonbell peppers and tomato.

5.3 Water Residue Profile

The drinking water residues used in the di etary risk assessment were provided by the

Environmental Fate and Effect s Division (EFED) in the following memorandum: “Bensulide: Drinking Water Exposure Assessment fo r Registration Review” (D428601, He Zhong, 09/14/2015) and incorporated directly into this dietary assessment. Water residues were incorporated in the DEEM-FCID into the food cat egories “water, direct, all sources” and “water, indirect, all sources.”

Drinking water from surface water sources ma y be subjected to water treatment through

chlorination. Kamel et al. (2009) demonstrated that the parent bensulide residues may be totally converted into bensulide oxon during chlorination processes. Therefore, a total toxic residue (TTR) approach based on the oxon equivalent wa s used for drinking water from surface water sources. The recommended estimated drinking wate r concentrations (EDW Cs) of the TTRs from surface water sources were genera ted with the Surface Water Concentration Calculator (SWCC)

model from the use scenario of the maximum exposure, Califo rnia lettuce, with three ground spray applications at 6 lb ai/A each and a minimum 4-month interval (Table 5.3.1).

Drinking water from groundwater sources is seldom subjected to chlorination; thus, conversion of bensulide to its oxon was only based on aerobic soil metabolism processes (13.8%). Therefore, recommended oxon EDWCs from groundw ater sources were modeled with PRZMGW based on the oxon soil conversion rate at 2. 12 lbs ai per acre following the use scenario on loamy sand soil in NC eastern coastal plain with two single bensu lide maximum granular applications at 16 lb ai per acre each at 4-mont h intervals (Table 5.3.1). Note that the EDWCs for groundwater were also obtained by modeling be nsulide at the maximum application rate; however, the EDWCs recommended by EFED are based on the oxon since these were higher than those for parent bensulide. Based on modeling, the highest residues were obtained forBensulide Human Health Risk Assessment DP No. D428598

Page 35 of 97 groundwater. In addition, the scenario that pr ovided the lowest EDWC (California Avocado; 3 applications at 6 lbs ai/A) was modeled to prov ide the lowest estimate of the exposure and risk for food and drinking water, see Table 5.3.2.

Table 5.3.1. Recommended Surface water and Groundwater EDWCs ( μ g/L) for Bensulide Oxon Surface Water Model: Tier II SWCC (v 1.106) 1 in 10 yr

Peak 1 in 10 yr Annual Average 30 yr Annual Average Ground Spray - CA Lettuce scenario (W23273.dvf) (6 lbs ai/acre for 3 app lications (2/1, 6/1, 10/1) 979 494 305

Groundwater Model: Tier 1 PRZM-GW

Peak

Values Post Breakthrough Average Breakthrough Time (Days)

NC Eastern Coastal Plain - (w13722Extended.dvf) 2.12 lbs ai/acre for 2 applications (3/1 and 7/1) 1,250 1,200 7,106

Table 5.3.2. Surface Wate r EDWCs for Bensulide TTRs

Scenario Concentration (μg/L) 1 in 10 yr

Peak 1 in 10 yr Annual Average 30 year Annual Average

CA Avocado (W23188.dvf) 179 100 73

For the acute and steady-state assessments, th e entire 30-year distribu tion of estimated daily concentrations in groundwater was incorporated into DEEM-FCID and used in the probabilistic analyses. For steady-state, the daily time seri es were recalculated using the 21-day rolling averages. In the 21-day rolling aver age distributions, the first data point is the average of days 1- 21, the second data point is the average of days 2- 22, the third data point is the average of days 3-23, etc. The estimated daily concentrations were adjusted by a 50x toxicity adjustment factor to account for the relative toxicity of bensulide ox on with respect to parent bensulide, refer to

section 5.4.1.

5.4 Dietary Risk Assessment

5.4.1 Description of Residue Data Used in Dietary Assessment

Relative Toxicity of the Oxon

In order to account for the relativ e toxicity of bensulide oxon with respect to parent bensulide, a CCA study is needed. However, EPA plans to m ove forward with bensulide human health risk assessment without toxicity data for bensulide’s oxon degradate. In lieu of bensulide-specific oxon CCA data, EPA will use an oxon toxicity adjust ment factor of 50x in its calculations. This

value considers the data deri ved toxicity adjustment fact or EPA has identified among oxon metabolites for other organophosphates, with an add itional margin of safety included due to the uncertainty in extrapolating oxon pot ency data across chemicals.

Anticipated ResiduesBensulide Human Health Risk Assessment DP No. D428598

Page 36 of 97 USDA Pesticide Data Program (PDP) monitoring data were incorpor ated in the dietary assessment. In years 2010 to 2013, USDA PDP analyzed several commodities for residues bensulide and its oxon separately. PDP monitoring data are availa ble for residues of bensulide and its oxon in carrots, carrots baby food, summer squash, cherry tomatoes, and lettuce. PDP monitoring data are only available for parent be nsulide for celery, winter squash, hot peppers, onion, canned spinach and frozen spinach. When the oxon analog was not measured, concentration adjustment factors of 1x were us ed; however, for leafy vegetables a factor of 9x was used since data suggest that residues of the oxon are likely to be higher than those of bensulide (see Appendix E). These factors were used in addition to the previously mentioned 50x toxicity adjustment factor. When the comm odity was not analyzed by the USDA PDP or translations were not possible, tolerance level residues were us ed. Anticipated residues using tolerances are based on the LOQ or 2 times th e LOQ (data adjusted due to loss of parent bensulide during storage) of the data acquisition method.

5.4.2 Percent Crop Treated Used in Dietary Assessment

The following maximum percent crop treated estimates (Updated Screening Level Usage Analysis Report for Bensulide, PC Code 009801; 07/10/2015) were used in the acute and steadystate dietary risk assessment for the following crops that are currently registered for bensulide: broccoli: 25%; Brussels spr outs: 5%; cabbage: 20%; cantalo upes: 40%; cauliflower: 20%; celery: 5%; cucumbers: 5%; honeydews: 30% ; lettuce: 40%; onions: 20%; peppers: 10%; pumpkins: 10%; spinach: 10%; squash: 15%; and watermelons: 10%. Percent of crop treated estimates were not provided for carrot, tomato, eggplant, okra and several non-representative crops under the cucurbit, leafy a nd brassica vegetables; 100% of crop treated were assumed for these crops.

5.4.3 Acute Dietary Risk Assessment

The acute dietary exposure estimates from food alone are below HED’s level of concern (LOC)

at the 99.9 th percentile of exposure for the general population and all population subgroups. The highest exposed population subgr oup was children 3-5 years ol d with an exposure of 0.005016 mg/kg/day occupying 46% of the aPAD. Exposures are above the LOC for drinking water only. For food and drinking water, using the drinking wa ter scenario that provided the highest EDWC (NC Cotton), the dietary exposure estima tes were >10,000 of the aPAD at the 95 th , 99 th and

99.9 th percentile of exposure for most population s ubgroups with All Infants (< 1 year old) having the highest exposure (Table 5.4.6). In addition, using the drinking water scenario (California Avocado) th at provided the lowest EDWC, th e dietary exposure estimates were

>1600% of the aPAD at the 99.9 th percentile of exposure for th e general populat ion and most population subgroups. For Adults 50-99 years old, fo r which the FQPA SF is 1x, exposures were above the LOC for food and drinking water (NC Cotton and CA Avocado) as well. In summary, acute aggregate (food and drinking water) dietar y exposure estimates are above HED’s level of

concern.Bensulide Human Health Risk Assessment DP No. D428598

Page 37 of 97 5.4.4 Steady-state Dietary Risk Assessment

The steady-state dietary exposur e estimates from food alone are below HED’s LOC at the 99.9 th
percentile of exposure for the general populat ion and all population subgroups. The highest exposed population subgroup was children 3-5 years old with an exposure of 0.004779 mg/kg/day occupying 80% of the ssPAD. Exposures are above the LOC for drinking water only. For food and drinking water, using the scenario that provided the highest EDWC, dietary exposure estimates were >10,000 of the ssPAD at the 95 th , 99 th and 99.9 th percentile of exposure for population subgroups with All Infants (< 1 ye ar old) having the highest exposure (Table 5.4.6). In addition, using the drinking water scen ario (California Avocado) that provided the lowest EDWC, the dietary exposure estimates were >2900% of the ssPAD at the 99.9 th percentile of exposure for the general population and all po pulation subgroups.For Adults 50-99 years old, for which the FQPA SF is 1x, exposures were above the LOC for food and drinking water (NC Cotton and CA Avocado) as well. In summary, steady-state aggr egate (food and drinking water) dietary exposure estimates are a bove HED’s level of concern.

5.4.5 Cancer Dietary Risk Assessment

Bensulide has been classified as not likely to be carcinogenic in humans vi a relevant routes of exposure; therefore, a cancer di etary assessment is not needed.

5.4.6 Summary Tables

Table 5.4.6.1. Summary of Acute Dietary (Food Only, and Food and Drinking Water) Exposure and Risk for Bensulide and for Bensulide Oxon (Expresse d as Bensulide Equivalents) at the 99.9 th Percentile.*

Population Subgroup Food Only Food and Water (NC Cotton) Food and Water (CA Avocado) Dietary Exposure (mg/kg/day) % aPAD Dietary Exposure (mg/kg/day) % aPAD Dietary Exposure (mg/kg/day) % aPAD

General U.S. Population 0.003459 31 7.200738 >10000 0.259261 2400 All Infants (<1 year old) 0.003299 30 15.584203 >10000 0.617566 5600 Children 1-2 years old 0.004436 40 10.366006 >10000 0.381599 3500 Children 3-5 years old 0.005016 46 6.774460 >10000 0.274069 2500 Children 6-12 years old 0.003835 35 6.321278 >10000 0.214996 2300 Youth 13-19 years old 0.002713 25 4.816789 >10000 0.180075 2000 Adults 20-49 years old 0.002241 20 5.199845 >10000 0.205208 1600 Adults 50-99 years old 0.002124 1.9 4.856943 4400 0.187992 170 Females 13-49 years old 0.002685 24 5.059084 >10000 0.202361 1800

* The subpopulation with the highest risk estimate is bolded.Bensulide Human Health Risk Assessment DP No. D428598

Page 38 of 97 Table 5.4.6.2. Summary of Steady-state Dietary (Food Only, and Food and Drinking Water) Exposure and Risk for Bensulide and for Bensulide Oxon (Expre ssed as Bensulide Equivalents) at the 99.9 th Percentile. *

Population Subgroup Food Only Food and Water (NC Cotton) Food and Water (CA Avocado) Dietary Exposure (mg/kg/day) % ssPAD Dietary Exposure (mg/kg/day) % ssPAD Dietary Exposure (mg/kg/day) % ssPAD

General U.S. Population 0.003454 58 7.197920 >10000 0.256468 4300 All Infants (<1 year old) 0.003322 55 15.581721 >10000 0.603403 >10000 Children 1-2 years old 0.004436 74 10.393019 >10000 0.378531 6300 Children 3-5 years old 0.004779 80 6.795017 >10000 0.267948 4500 Children 6-12 years old 0.003836 64 6.315285 >10000 0.212895 3500 Youth 13-19 years old 0.002710 45 4.781498 >10000 0.176266 2900 Adults 20-49 years old 0.002240 37 5.194808 >10000 0.200449 3300 Adults 50-99 years old 0.002121 3.6 4.851935 8100 0.182459 300 Females 13-49 years old 0.002687 45 5.053817 >10000 0.196688 3300

* The subpopulation with the highest risk estimate is bolded.

6.0 Residential (Non-Occupational) Exposure/Risk Characterization

6.1 Residential Handler Exposure

HED uses the term “handlers” to describe those individuals who are involved in the pesticide application process. HED believes that there are distinct tasks related to applications and that exposures can vary depending on the specifics of each task. Residential handlers are addressed somewhat differently by HED as homeowners are assumed to complete all elements of an application without use of any protective equipment.

The quantitative exposure/risk a ssessment developed for reside ntial handlers is based on the following scenarios:

 Mixing/loading/applying liqui d and granular formulati ons dispersed by hand to residential turf/lawns, and

 Mixing/loading/applying liquid and granular formulations with handheld equipment to

residential turf/lawns.

Residential Handler Exposu re Data and Assumptions A series of assumptions and exposure factors serv ed as the basis for completing the residential handler risk assessments. Each assump tion and factor is detailed below.

Application Rate: Application rates are listed in Table 3.3.

Unit Exposures and Area Treated or Amount Handled:Bensulide Human Health Risk Assessment DP No. D428598

Page 39 of 97 Unit exposure values and estimates for area treat ed or amount handled were taken from HED’s

2012 Residential SOPs 5

.

Exposure Duration: Residential handler exposure is a ssessed as steady-state in duration.

Body Weight: For adults, when an endpoint is not sex-specific (i.e., the endpoints are based on developmental or fetal effects) a body weight of 80 kg is typically used in risk assessment; however, in this case, a female-specific body weight of 69 kg was us ed. While the endpoint of concern, RBC AChE inhibition, is not sex-specific, th e female-specific body weight was used to protect for pregnant women due to uncertainty in the human dose- response relationship for neurodevelopmental effects (See Section 4.4).

Residential Handler Non-Cancer Ex posure and Risk Estimate Equations The algorithms used to estimate exposure and dos e for residential handlers can be found in the

2012 Residential SOPs 6

.

Combining Exposures/Risk Estimates:

A total aggregated risk index (ARI) was used since the LOCs for dermal exposure (1000) and inhalation exposure (3000) are differe nt. The target ARI is 1; ther efore, ARIs of less than 1 are risk estimates of concern. The aggregate risk index (ARI) was calculated as follows.

Aggregate Risk Index (ARI) = 1÷ [(Dermal LOC ÷ Dermal MOE) + (Inhalation LOC ÷ Inhalation MOE)]

Summary of Residential Handler Non- Cancer Exposure and Risk Estimates

A summary of residential handler risk estimates is provided in Table 6.1.1 below. Most

residential handler risk estimates are of concern (ARI < 1).

5 Available: http://www2.epa.gov/pesticide-scie nce-and-assessing-pesticide-risks/ standard-operating-proceduresresidential-pesticide

6 Available: http://www2.epa.gov/pesticide-scie nce-and-assessing-pesticide-risks/ standard-operating-proceduresresidential-pesticideBensulide Human Health Risk Assessment DP No. D428598Page40of97Table 6.1.1. Residential Handler Non-cancerExposure and Risk Estimates for Bensulide.Exposure ScenarioLevel ofConcernDermal UnitExposure(mg/lb ai)InhalationUnit Exposure(mg/lb ai)MaximumApplicationRate1Area Treated orAmount HandledDaily2DermalInhalationTotalDose(mg/kg/day)3MOE4Dose(mg/kg/day)5MOE6ARI7Mixer/Loader/ApplicatorLiquid Concentrate,Handwand, Lawns1000 fordermal3000 forinhalation63 0.018 0.16 lb ai/gal 5 gallons 0.073820.000229,0000.081Ready-to-use, hose endsprayer, Lawns6.26 0.034 8.7 lb ai/acre 0.5 acres 0.0391500.00212,8000.13Liquid, Backpack,Lawns130 0.14 0.16 lb ai/gal 5 gallons 0.15400.00163,7000.039Granule, Push typerotary spreader, Lawns0.81 0.0026 12.5 lb ai/acre 0.5 acres 0.00738200.000225,0000.75Granule, belly grinder,lawns360 0.0390.00029 lb ai/ft21200 ft20.18330.000231,0000.033Granule, Spoon, Lawns 6.2 0.087100 ft20.00026 23,000 0.000037160,00016Granule, Cup, Lawns 0.110.013 0.0000046 1,300,000 0.00000551,100,000290Granule, Handdispersal, Lawns160 0.38 0.00678900.0001638,0000.83Granule, Shaker can,Lawns0.11 0.013 0.0000046 1,300,000 0.00000551,100,0002901 Based on registered labels (see Table 3.3).2 Based on HED’s 2012 Residential SOPs (http://www2.epa.gov/pesticide-science-and-assessing-pesticide-risks/standard-operating-procedures-residential-pesticide).3 Dermal Dose = Dermal Unit Exposure (mg/lb ai) × Application Rate (lb ai/acre, ft2or gal) × Area Treated or Amount Handled (A or ft2/day or gallons/day) × DermalAbsorption Factor (10%) ÷ Body Weight (69 kg).4 Dermal MOE = Dermal NOAEL (6 mg/kg/day) ÷ Dermal Dose (mg/kg/day).5 Inhalation Dose = Inhalation Unit Exposure (mg/lb ai) × ApplicationRate (lb ai/acre, ft2or gal) × Area Treated or Amount Handled (A or ft2/day or gallons/day) ÷ Body Weight(69 kg).6 Inhalation MOE = Inhalation NOAEL (6 mg/kg/day) ÷ Inhalation Dose (mg/kg/day).7 ARI = Aggregate Risk Index = 1÷ [(Dermal LOC ÷ Dermal MOE)+ (Inhalation LOC ÷ Inhalation MOE)]Bensulide Human Health Risk Assessment DP No. D428598

Page 41 of 97 6.2 Residential Post-Application Exposure

There is the potential for post-app lication exposure for individuals e xposed as a result of being in an environment that has been pr eviously treated with bensulide. The quantitative exposure/risk assessment for residential post-application e xposures is based on th e following scenarios:

 Dermal exposure from high contact with treated turf (adults and ch ildren 1 to < 2 years old),

 Dermal exposure from golfing (adults and youth 11 to < 16 years old and youth 6 to < 11 years old),

 Dermal exposure from mowing treated turf (adults and youth 11 to < 16 years old),

 Incidental ingestion (i.e., hand-to-mouth, object-to-mouth, soil ingestion exposure) from contact with treated turf (chi ldren 1 to < 2 years old), and

 Episodic granular ingestion (c hildren 1 to < 2 years old).

The lifestages selected for each pos t-application scenario are based on an analysis provided as an Appendix in the 2012 Residential SOPs 7 . While not the only life stage potentially exposed for these post-application scenarios, the lifestage th at is included in the quantitative assessment is health protective for the exposures and risk esti mates for any other poten tially exposed lifestage.

Residential Post-application E xposure Data and Assumptions A series of assumptions and exposure factors serv ed as the basis for completing the residential post-application risk assessment. Each assumpti on and factor is detailed in the 2012 Residential

SOPs7.

Application Rate: Application rates are listed in Table 3.3.

Body Weight For adults, when an endpoint is not sex-specific (i.e., the endpoints are based on developmental or fetal effects) a body weight of 80 kg is typically used in risk assessment; however, in this case, a female-specific body weight of 69 kg was us ed. While the endpoint of concern, RBC AChE inhibition, is not sex-specific, th e female-specific body weight was used to protect for pregnant women due to uncertainty in the human dose- response relationship for neurodevelopmental effects (See Section 4.4). Fo r children, body weights of 57, 32 and 11 kg was used to assess exposure to children 11 to <16 years, 6 to <11 years, and 1 to <2 years old.

Turf Transferable Residue (TTR) Data:

Liquid Formulations:

7 Available: http://www2.epa.gov/pesticide-scie nce-and-assessing-pesticide-risks/ standard-operating-proceduresresidential-pesticideBensulide Human Health Risk Assessment DP No. D428598

Page 42 of 97 Chemical-specific TTR data are available fo r bensulide and are summarized in Table 6.2.1 (review: D413875, 10/29/13, A. Rivera-Lupiañ ez). The study includes TTR data on bensulide and its metabolite, bensulide oxon, th at dislodged from turf treated with a liquid formulation containing bensulide at a rate of 12.5 lb ai/A. The product was watered in immediately following the appli cation. Residues were sampled using the modified California Roller technique. First- order dissipation kineti cs was assumed in order to generate dissipation curves for bens ulide and combined residues of bensulide and bensulide oxon. The summary of statistics includes only post- irrigation measurements as the product labels require the product to be watered in. Due to the differences in the dissipation of bensulide and th e oxon, residues of the oxon were adjusted by the toxicity adjustment factor (TAF; oxon residue, ug/cm 2 * 50X TAF), and tota l residues (bensulide + adjusted oxon) were used to determine th e risk resulting from exposures following bensulide applications. For assessment of residential pos t-application exposures, the predicted day 0 combined residue (0.479 ug/cm 2 ) was used in the exposure calculations (see Table 6.2.1 below).

Table 6.2.1. Regression Summary for Turf Treated with BENSUMEC 4LF (MRID 44799001)

Statistic Bensulide Bensulide

oxon Combined

residues Combined Residue with

50x factor for oxon 1

Actual Application Rate (lb ai/A) 12.6

Actual Average Residues 8-12 hours after application (μg/cm 2 ) (post-irrigation ) 0.2093 0.0057 0.2144 0.4627

Predicted Day 0 Residues (μg/cm 2 ) (post-irrigation ) 0.201 0.002 0.206 0.479

Slope -0.27 -0.049 -0.271 -0.303

Half-life (days) 2.6 14.2 2.6 2.3

R 2 0.897 0.0285 0.8934 0.8123

Bolded value represents residue value used in post-application exposure calculations.

1 Combined residue, ug/cm 2 = [(oxon residue, ug/cm 2 ) * 50X TAF] + [bensulide residue, ug/cm 2 )

Solid Formulations : Chemical-specific TTR data are not available fo r solid formulations a pplied to turf; liquid TTR data were used as surrogate. This is co nsidered a health prot ective approach since, in general, granular formulations tend to re sult in lower percent transfer from turf than do liquid formulations (e.g., the 2012 Residential SO P turf default percent transfer factor is 1% for liquids and 0.2% for granulars).

Exposure Duration: The exposure duration for reside ntial post-application exposures is steady-state. Granule ingestion is considered episodic and thus is an acute duration.

Residential Post-application Non-Ca ncer Exposure and Risk EquationsBensulide Human Health Risk Assessment DP No. D428598

Page 43 of 97 The algorithms used to estimate residential pos t-application exposure a nd dose can be found in

the 2012 Residential SOPs 8

.

Combining Exposure and Risk Estimates Since dermal and incidental oral exposure rout es share a common toxico logical endpoint, risk

estimates have been combined for those routes. The incidental oral scenarios (i.e., hand-tomouth and object-to-mouth) should be considered inter-related, a nd it is likely that they occur interspersed amongst each other across time. Combining these scenarios with the dermal exposure scenario would be overly-conservative because of the conservative nature of each individual assessment. Therefore, the post-appl ication exposure scenarios that were combined for children 1 < 2 years old are the dermal a nd hand-to-mouth scenarios. This combination should be considered a protective estimate of children’s exposure.

Summary of Residential Post-application Non-Cancer Exposure and Risk Estimates A summary of the residential pos t-application exposure and risk estimates for bensulide and its oxon is in Tables 6.2.2 (for liquid formulations) a nd 6.2.3 (for solid formulations) below. Risk estimates are of concern (MOEs < 1000) for derm al exposure for adults and children conducting high exposure activities on treated turf; for dermal exposure for adults and youths golfing; for hand-to-mouth exposure for children on treated turf; and for episodi c granule ingestion exposure.

Table 6.2.2. Residential Post-Application Non-Cancer Exposure and Risk Estima tes for Bensulide + Oxon (Liquid Formulations).

Lifestage Post-application Exposure

Scenario Application

Rate 1 Dose (mg/kg/day) 2 MOEs (LOC = 1000) 3 Combined Routes (X indicates

included in Combined MOE) Combined MOEs (LOC = 1000) 4 Use Site Route of Exposure

Adult

Lawns/ Turf Dermal – Turf

12.5 lb ai/A 0.187 32

NA Dermal - Mowing 0.0038 1,600
Dermal – Golfing 0.0147 410

Youth (11 to < 16 years) Dermal- Mowing 0.00378 1,600
Dermal – Golfing 0.0148 410
Youth (6 to <

11 years) Dermal- Golfing 0.0174 350

Child (1 to <

2 years) Dermal - Turf 0.32 19 X 16 Hand-to-Mouth 0.0656 91 X
Object-to-Mouth 0.00199 3,000 NA

Soil Ingestion 0.00042 14,000

1 Based on registered labels (see Table 3. 3). Predicted Day 0 combined (bensulide + adjusted oxon) residue value (0.479 ug/cm 2 ; from MRID 44799001) used in calculations. 2 Dose (mg/kg/day) algorithms pr ovided in 2012 Residential SOPs ( http://www2.epa.gov/pesticide-sc ience-and-assessing-pesticiderisks/standard-operating-procedures-residential-pesticide ).

3 MOE = Dermal and Incidental Oral P OD (6 mg/kg/day) ÷ Dose (mg/kg/day). 4 Combined MOE = 1 ÷ (1/dermal MOE) + (1 /incidental oral MOE), where applicable.

8 Available: http://www2.epa.gov/pesticide-scie nce-and-assessing-pesticide-risks/ standard-operating-proceduresresidential-pesticideBensulide Human Health Risk Assessment DP No. D428598

Page 44 of 97 Table 6.2.3. Residential Post-Applic ation Non-Cancer Exposure and Risk Estimates for Bensulide + Oxon (Solid Formulations).

Lifestage Post-application Exposure

Scenario Application

Rate 1 Dose (mg/kg/day) 2 MOEs (LOC = 1000) 3 Combined Routes (X indicates

included in Combined MOE) Combined MOEs
(LOC = 1000) 4 Use Site Route of Exposure

Adult

Lawns/ Turf Dermal – Turf 12.5 lb ai/A 0.2082 29

NA Dermal - Mowing 0.0038 1,600
Dermal – Golfing 16 lb ai/A 0.0188 320

Youth (11 to < 16 years) Dermal- Mowing 12.5 lb ai/A 0.00378 1,600
Dermal – Golfing

16 lb ai/A 0.0189 320
Youth (6 to <

11 years) Dermal- Golfing 0.0222 270

Child (1 to <

2 years) Dermal - Turf

12.5 lb ai/A 0.3527 17 X 16 Hand-to-Mouth 0.0325 180 X
Object-to-Mouth 0.00199 3,000

NA

Soil Ingestion 0.00042 14,000
Episodic Granule Ingestion (12.5% ai) 3.41 3.2

1 Based on registered labels (See Table 3.3). Predicted Day 0 combined (bensulide + adjusted oxon) residue value (0.479 ug/cm 2 ; from MRID 44799001) used in calculations. 2 Dose (mg/kg/day) algorithms pr ovided in 2012 Residential SOPs ( http://www2.epa.gov/pesticide-sc ience-and-assessing-pesticiderisks/standard-operating-procedures-residential-pesticide ).

3 MOE = Dermal and Incidental Oral P OD (6 mg/kg/day) ÷ Dose (mg/kg/day). 4 Combined MOE = 1 ÷ (1/dermal MOE) + (1 /incidental oral MOE), where applicable.

6.4 Residential Risk Estimates fo r Use in Aggregate Assessment

As the residential turf scenarios are risks of concern, there are no residential risk estimates recommended for steady state aggregate assessment.

6.5 Residential Bystander Post-application Inhalation Exposure

Volatilization of pes ticides may be a source of post-ap plication inhala tion exposure to individuals nearby pesticide app lications. The Agency sought expert advice and input on issues

related to volatilization of pesticides from its Federal Insec ticide, Fungicide, and Rodenticide Act Scientific Advisory Panel (S AP) in December 2009, and received the SAP’s final report on March 2, 2010 (http://www.regulations.gov/#! documentDetail;D=EPA-HQ-OPP-2009-0687- 0037). The Agency has evaluated the SAP report and has developed a Volatilization Screening Tool and a subsequent Volat ilization Screening Analysis (http://www.regulations.gov/#! docketDetail;D=EPA-HQ-OPP-2014- 0219). During Registration Review, the Agency will u tilize this analysis to determine if da ta (i.e., flux studies, route-specific inhalation toxicological studi es) or further analysis is required for bensulide.

The California Department of Pesticide Regulati on (DPR) has released a draft report on its air monitoring network for public comment. In 2011, DPR established a monitoring network to sample ambient air for multiple pesticides in three communities on a regular basis. The draft report of results for the mon itoring in 2014 is available at http://www.cdpr.ca.gov/docs/emon/ airinit/air_network_results.htm. In the draft Air Monitoring Network Results for 2014 report, there were 0 detections of bensulide of 157 samples. Furthermore, in the 2012 and 2013 reports, there were 0 detections of bensulide. In the 2011Bensulide Human Health Risk Assessment DP No. D428598

Page 45 of 97 report, there were 5 detects of bensulide of 142 samples; all detects were below the quantitation

limit.

6.6 Non-Occupational Spray Drift Exposure and Risk Estimates

Off-target movement of pesticides can occur vi a many types of pathways and it is governed by a variety of factors. Sprays that are released and do not deposit in the application area end up offtarget and can lead to exposures to those it may directly cont act. They can also deposit on

surfaces where contact with residues can eventua lly lead to indirect exposures (e.g., children playing on lawns where residues ha ve deposited next to treated fields). The potential risk

estimates from these residues can be calculated using drift modeling onto 50 feet wide lawns coupled with methods employed for resident ial risk assessments for turf products.

The approach to be used for quantitatively incorp orating spray drift into risk assessment is based on a premise of compliant applications which, by definition, should not result in direct exposures to individuals because of existing label languag e and other regulatory requirements intended to prevent them. 9 Direct exposures would include inhala tion of the spray plume or being sprayed directly. Rather, the exposures addressed here are thought to occur indirectly through contact with impacted areas, such as residential lawn s, when compliant applications are conducted. Given this premise, exposures for children (1 to <2 years old) and adults who have contact with turf where residues are assumed to have deposited via spray drift thus re sulting in an indirect exposure are the focus of this analysis anal ogous to how exposures to turf products are

considered in risk assessment.

For adults, when an endpoint is not sex-specific (i.e., the endpoints are based on developmental or fetal effects) a body weight of 80 kg is typically used in risk assessment; however, in this case, a female-specific body weight of 69 kg was us ed. While the endpoint of concern, RBC AChE inhibition, is not sex-specific, th e female-specific body weight was used to protect for pregnant women due to uncertainty in the human dose- response relationship for neurodevelopmental effects (See Section 4.4).

In order to evaluate the drift potential and associ ated risks, an approach based on drift modeling coupled with techniques used to evaluate residential uses of pest icides was utilized. Essentially, a residential turf assessment based on exposure to deposited residues has been completed to address drift from the agricultural applications of bensulide. In the sp ray drift scenario, the deposited residue value was determined based on the amount of spray drift that may occur at varying distances from the edge of the treated field using the AgDrift ® (v2.1.1) model and the Residential Exposure Assessment Standard Operating Procedures Addenda 1: Consideration of Spray Drift Policy . Once the deposited residue values were determined, the remainder of the spray drift assessment was based on the algorithms and input valu es specified in the recently revised (2012) Standard Operating Procedures For Re sidential Risk Assessment (SOPs)

.

For bensulide, chemical-specific tu rf transferable residue (TTR) da ta are available and were used for assessment of spray drift risks. See Section 6.2 for a description of the TTR data. The data

9 This approach is consistent with the requirem ents of the EPA’s Worker Protection Standard.Bensulide Human Health Risk Assessment DP No. D428598

Page 46 of 97 include measurements on bensulide and the oxon. For assessment of exposures resulting from spray drift, the predicted day 0 combined (b ensulide + adjusted oxon) residue value (0.479 ug/cm 2 ) was adjusted for differences in applicatio n rate between the study and the registered agricultural uses, and the adjusted residue value was us ed in the exposure calculations.

A screening approach was develope d based on the use of the AgDrift ® model in situations where specific label guidance that defines app lication parameters is not available. 10 AgDrift ® is appropriate for use only when app lications are made by aircraft, airblast orchard sprayers, and groundboom sprayers. When AgDrift ® was developed, a series of sc reening values (i.e., the Tier 1 option) were incorporated in to the model and represent eac h equipment type and use under varied conditions. The screening options spec ifically recommended in this methodology were selected because they are plausible and repres ent a reasonable upper bound level of drift for common application methods in ag riculture. These screening opti ons are consistent with how spray drift is considered in a number of ecological risk assessmen ts and in the process used to develop drinking water concentrations used for risk assessment. In all cases, each scenario is to be evaluated unless it is not pl ausible based on the anticipated use pattern (e.g., herbicides are not typically applied to tree ca nopies) or specific label prohibiti ons (e.g., aerial applications are not allowed). Table 6.6.1 provides the screening level drift related risk estimates. In many cases, risk estimates are of concern when the scr eening level estimates for spray drift are used as the basis for the analysis. In order to account for this issue and to provide additional risk management options, additional spray drift depos ition fractions were also considered. These drift estimates represent plausible options for pesticide labels.

Combined Risk Estimates from Lawn Deposition Adjacent to Applications

The spray drift risk estimates are based on an estimated deposited residue concentration as a result of the screening level agricultural applica tion scenarios. Bensulide is registered in both liquid and granular formulation end-use products. Granular fo rmulations, applied as solid materials and no liquid spray, have different drift patterns than liqui d sprays, and as such, need to be considered in a separate analysis. Howeve r, from a human health perspective, off-site movement of granular products would result in lower risk estimates than those for liquid products ( e.g. , less drift occurs and there is less exposure uptake for gr anules). In most cases, pesticides also have liquid end-use products and an analysis for them would be protective of potential risks from granular drift; thus , granular products are not assessed.

Bensulide is registered on vege table crops and golf courses, and can be applied via groundboom equipment at a maximum single application rate of 6 lb ai/A for vegetabl e crops (9 lb ai/A on SLN labels) and 12.5 lb ai/acre for golf course s. The recommended drift scenario screening level options are listed below:

 Groundboom applications are based on the AgDrift ® option for high boom height and using very fine to fine spray type using the 90 th percentile results.

10 http://www.agdrift.com/Bensulide Human Health Risk Assessment DP No. D428598

Page 47 of 97 In addition to the screening le vel spray drift scenarios described above, additional results are provided which represent viable drift reduction technologies (DRTs) that represent potential risk management options. In particular, different spra y qualities have been considered as well as the impact of other application conditions (e .g., boom height and crop canopy conditions).

Dermal risk estimates were calculated for adults. Dermal and incidental oral risk estimates for children (1 to <2 years old) were combined because the toxicity e ndpoint for each route of exposure is the same (RBC AChE inhibition). The total applicable LOC is 1000, so MOEs <1000 represent risk estimates of concern.

Risk estimates related to spray dr ift are of concern at various dist ances from the edge of the field for adults and children (1 to <2 years) dependi ng on the spray drift scenar io. Adult and children

risk estimates are summarized in Table 6.6.1. For adults, the screening le vel scenario indicates

the LOC is exceeded at a distance of less than 25 f eet for applications to vegetables and less than 75 feet for applications to golf courses. For ch ildren, the screening level scenario indicates the

LOC is exceeded at a distance of less than 75 feet for applications to vegetables and 150 feet for applications to golf courses. Drift reduction technologies, such as using coarser sprays and lowering boom height for groundboom sprayers, redu ces risk concerns; howe ver, there are still risk estimates of concern at the field edge for some scenarios.Bensulide Human Health Risk Assessment DP No. D428598Page48of97Table 6.6.1. Spray Drift RiskEstimate Summary for Bensulide.Crop /ApplicationTypeSpray Type/NozzleConfigurationApplicationRate(lb ai/A)EstimatedTTR(ug/cm2)MOE at Different Distances from Edge of FieldLOC = 1000At Edge10Feet25 Feet50 Feet75 Feet100 Feet125 feet150 feet200 feet250 feet300 feetAdults (Dermal Exposure Only); Vegetable Crops (6 lb ai/acre)Vegetable /GroundboomScreening LevelHigh Boom Veryfine to Fine6 0.22993607201,2001,9002,7003,3003,9004,8006,1008,3009,500Low Boom Veryfine to Fine7802,1003,3005,1006,7008,3009,50011,00013,00017,00022,000High Boom Fineto Medium /Coarse1,4003,5005,1007,4009,50011,00013,00013,00017,00022,00022,000Low Boom Fine toMedium / Coarse2,0005,6008,30011,00013,00017,00022,00022,00033,00033,00033,000Adults (Dermal Exposure Only); Vegetable Crops (SLN rate of 9 lb ai/acre)Vegetable /GroundboomScreening LevelHigh Boom Veryfine to Fine9 0.3452404807901,3001,8002,2002,6003,2004,0005,6006,400Low Boom Veryfine to Fine5201,4002,2003,4004,4005,6006,4007,4008,90011,00015,000High Boom Fineto Medium /Coarse9102,3003,4004,9006,4007,4008,9008,90011,00015,00015,000Low Boom Fine toMedium / Coarse1,3003,7005,6007,4008,90011,00015,00015,00022,00022,00022,000Adults (Dermal Exposure Only); Golf CoursesGolf Course/GroundboomScreening LevelHigh Boom Veryfine to Fine12.5 0.4791703405709101,3001,6001,9002,3002,9004,0004,600Low Boom Veryfine to Fine3801,0001,6002,5003,2004,0004,6005,3006,4008,00011,000High Boom Fineto Medium /Coarse6501,7002,5003,6004,6005,3006,4006,4008,00011,00011,000Low Boom Fine toMedium / Coarse9702,7004,0005,3006,4008,00011,00011,00016,00016,00016,000Children (1 to < 2 years old) (Dermal and IncidentalOral Exposure); Vegetable Crops (6 lb ai/acre)Bensulide Human Health Risk Assessment DP No. D428598Page49of97Table 6.6.1. Spray Drift RiskEstimate Summary for Bensulide.Crop /ApplicationTypeSpray Type/NozzleConfigurationApplicationRate(lb ai/A)EstimatedTTR(ug/cm2)MOE at Different Distances from Edge of FieldLOC = 1000At Edge10Feet25 Feet50 Feet75 Feet100 Feet125 feet150 feet200 feet250 feet300 feetVegetable /GroundboomScreening LevelHigh Boom Veryfine to Fine6 0.22991703505809301,3001,6001,9002,3002,9004,1004,600Low Boom Veryfine to Fine3801,0001,6002,5003,2004,1004,6005,4006,5008,10011,000High Boom Fineto Medium/Coarse6601,7002,5003,6004,6005,4006,5006,5008,10011,00011,000Low Boom Fine toMedium/Coarse9802,7004,1005,4006,5008,10011,00011,00016,00016,00016,000Children (1 to < 2 years old) (Dermal and Incidental OralExposure); Vegetable Crops (SLN rate of 9 lb ai/acre)Vegetable /GroundboomScreening LevelHigh Boom Veryfine to Fine91202303906208601,1001,3001,5002,0002,7003,100Low Boom Veryfine to Fine2506801,1001,7002,2002,7003,1003,6004,3005,4007,200High Boom Fineto Medium/Coarse4401,1001,7002,4003,1003,6004,3004,3005,4007,2007,200Low Boom Fine toMedium/Coarse6501,8002,7003,6004,3005,4007,2007,20011,00011,00011,000Children (1 to < 2 years old) (Dermal and Incidental Oral Exposure); Golf CoursesGolf Course/GroundboomScreening LevelHigh Boom Veryfine to Fine12.5 0.479831702804406207809201,1001,4001,9002,200Low Boom Veryfine to Fine1804907801,2001,6001,9002,2002,6003,1003,9005,200High Boom Fineto Medium/Coarse3208201,2001,7002,2002,6003,1003,1003,9005,2005,200Low Boom Fine toMedium/Coarse4701,3001,9002,6003,1003,9005,2005,2007,8007,8007,800Bolded values are below the LOC of 1000.Bensulide Human Health Risk Assessment DP No. D428598

Page 50 of 97 7.0 Aggregate Exposure/Risk Characterization

In accordance with the FQPA, HED must consider and aggregate (add) pesticide exposures and risks from three major sources: food, drinking water, and residential exposures. In an aggregate assessment, exposures from relevant sources are added together and compared to quantitative estimates of hazard (e.g., a NOAEL or PAD), or th e risks themselves can be aggregated. When aggregating exposures and risks from various sources, HED consider s both the route and duration of exposure.

7.1 Acute Aggregate Risk

The acute aggregate risk assessment combines oral exposure through food and drinking water which is represented by the acute dietar y assessment, refer to Section 5.4.3.

7.2 Steady-state Aggregate Risk

The steady-state aggregate assessment combines steady-state dietary (food and water) and residential exposures. Because there are risks of concern associated with dietary and residential exposure, an aggregate risk assessment was not conducted.

7.3 Cancer Aggregate Risk

Bensulide has been classified as not likely to be carcinogenic in humans vi a relevant routes of exposure; therefore, a cancer aggr egate assessment is not needed.

8.0 Cumulative Exposure/Risk Characterization

OPs, like bensulide, share the ability to inhibit AChE thr ough phosphorylation of the serine residue on the enzyme leading to accumulati on of acetylcholine and ultimately cholinergic neurotoxicity. This shared MOA/AOP is the basis for the OP common mechanism grouping per

OPP’s Guidance For Identifying Pesticide Chemic als and Other Substances that have a Common Mechanism of Toxicity (USEPA, 1999). The 2002 and 2006 CRA s used brain AChE inhibition in female rats as the source of dose response da ta for the relative potency factors and PODs for each OP, including bensulide. Prior to the co mpletion of Registration Review, OPP will update

the OP CRA on AChE inhibition to incorporate new toxi city and exposure information available

since 2006.

As described in Section 4.4, OPP has retained the FQPA Safety Factor for OPs, including bensulide, due to uncertainties associated wi th neurodevelopmental effects in children and exposure to OPs. There is a lack of an established MOA/AOP for the neurodevelopment outcomes which precludes the Agency from fo rmally establishing a common mechanism group per the Guidance For Identifying Pesticide Chem icals and Other Substances that have a Common Mechanism of Toxicity (USEPA, 1999) based on that outcome. Moreover, the lack of a recognized MOA/AOP and other uncertainties w ith exposure assessment in the epidemiology studies prevent the Agency from establishing a causal relationship between OP exposure andBensulide Human Health Risk Assessment DP No. D428598

Page 51 of 97 neurodevelopmental outcomes. Th e Agency will continue to ev aluate the epidemiology studies associated with neurodevelopmental outcomes a nd OP exposure prior to the release of the revised DRA. During this period, the Agency will determine whether or not it is appropriate to apply the draft guidance document entitled, Pesticide Cumulative Risk Assessment: Framework for Screening Analysis for the neurodevelopment outcomes.

9.0 Occupational Exposure/Risk Characterization

Exposure to bensulide is assessed for handler s cenarios; exposure to bensulide and bensulide oxon was assessed for post-application scenarios.

9.1 Steady-State Handler Risk

HED uses the term handlers to describe those individuals who are invo lved in the pesticide application process. HED believe s that there are distinct job functions or tasks related to applications, and exposures can vary depending on the specifics of each task. Job requirements (amount of chemical used in each application), the kinds of equipment used, the target being treated, and the level of protection used by a ha ndler can cause exposure levels to differ in a manner specific to each application event.

Based on the anticipated use patterns and curr ent labeling, types of equipment and techniques that can potentially be used, occupational handler exposure is expected from the proposed uses. The quantitative exposure/risk a ssessment developed for occupati onal handlers is based on the following scenarios:

 Mixing/loading granules fo r tractor application,

 Mixing/loading liquids for chemig ation and groundboom application,

 Applying granules via tractor,

 Applying sprays via groundboom equipment,

 Mixing/loading/applying liqui ds via handgun equipment, and

 Mixing/loading/applying gra nules via rotary spreader.

Occupational Handler Exposur e Data and Assumptions

A series of assumptions and exposure factors serv ed as the basis for completing the occupational handler risk assessments. Each assumption and fact or is detailed below on an individual basis.

Application Rate : A summary of application rate s is provided in Table 3.3.

Unit Exposures: It is the policy of HED to use the best av ailable data to assess handler exposure. Sources of generic handler data, used as surrogate data in the absence of chemical-specific data, include PHED 1.1, the AHETF database, the Outdoor Residential Exposure Task Force (ORETF) database, or other registrant-submitted occupational exposure studies. Some of these data are proprietary (e.g., AHETF data) and subject to the data pr otection provisions of FIFRA. The standard values recommended for use in pred icting handler exposure that are used in thisBensulide Human Health Risk Assessment DP No. D428598

Page 52 of 97 assessment, known as “unit exposures”, are outlin ed in the “Occupational Pesticide Handler Unit Exposure Surrogate Reference Table 11 ”, which, along with additional information on HED policy on use of surrogate data, including descrip tions of the various sources, can be found at the Agency website 12

.

Area Treated or Amount Handled: Based on ExpoSAC Policy 9.1, the area treated or amount handled is assumed to be:

 40 acres for tractor or groundboom a pplications to golf courses,

 350 acres for chemiga tion applications,

 80 acres for groundboom applications to typical field crops (vegetables),

 1000 gallons for handgun applications to field crops (vegetables), and

 5 acres for handgun/rotary spreader applications to golf courses.

Exposure Duration: For bensulide, based on the proposed use, steady-state exposure is expected.

Mitigation/Personal Protective Equipment: Estimates of dermal and inhalation exposure were calculated for various levels of personal protect ive equipment (PPE). Results are presented for the label-required PPE, and also with various leve ls of additional PPE, as necessary. A summary of PPE requirements in listed in Table 3.3.

Body Weight: For adults, when an endpoint is not sex-specific (i.e., the endpoints are based on developmental or fetal effects) a body weight of 80 kg is typically used in risk assessment; however, in this case, a female-specific body wei ght of 69 kg was used. While the endpoint of concern, RBC AChE inhibition, is not sex-specific, the female-specific body weight was used to protect for pregnant women due to uncertainty in the human dose-response relationship for neurodevelopmental eff ects (See Section 4.4).

Occupational Handler Non-Cancer E xposure and Risk Estimate Equations The algorithms used to estimat e non-cancer exposure and dose fo r occupational handlers can be found in the occupational and residential e xposure (ORE) memo for bensulide (D428877, A. Gavalek and K. Lowe, 03/03/2016).

Combining Exposures/Risk Estimates: A total aggregated risk index (ARI) was used since the LOC values for dermal exposure (1000) and inhalation exposure (3000) are di fferent. The target ARI is 1; therefore, ARIs of less than 1 are risk estimates of concern. The aggregate risk index (ARI) was calculated as follows.

Aggregate Risk Index (ARI) = 1÷ [(Dermal LOC ÷ Dermal MOE) + (Inhalation LOC ÷ Inhalation MOE)]

11 Available: http://www2.epa.gov/sites/production/files/2015 -09/documents/handler-exposure-table-2015.pdf

12 Available: http://www2.epa.gov/pesticide-scie nce-and-assessing-pesticide-risks/ occupational-pesticide-handlerexposure-dataBensulide Human Health Risk Assessment DP No. D428598

Page 53 of 97 Summary of Occupational Handler Non-Cancer Exposure and Risk Estimates A summary of occupational handler risk estimates for bensulide with the label-required PPE is provided in Table 9.1.1 below. With the labe l-required PPE, all handler risk estimates (combined dermal and inhalation) are of con cern (ARI < 1). A summa ry of handler risk estimates with additional PPE/ engineering contro ls to mitigate risks is provided in Table 9.1.2;

most handler risk estimates are still of concern with the maximum PPE/ engineering controls.Bensulide Human Health Risk Assessment DP No. D428598Page54of97Table 9.1.1. Occupational Handler Non-Cancer Exposure and Risk Estimates for Bensulide (with label-required PPE).Exposure ScenarioCrop or TargetDermal UnitExposure(μg/lb ai)1Inhalation UnitExposure(μg/lb ai)1MaximumApplicationRate2AreaTreated orAmountHandledDaily3DermalInhalationTotalDose(mg/kg/day)4MOE5(LOC =1000)Dose(mg/kg/day)6MOE7(LOC =3000)ARI8Mixer/LoaderM/L, Granule, TractorApplicationGolf Course DL/G: 3.4 PF 5: 0.3416 lb ai/A 40 A 0.00316 1,900 0.003161,900 0.48M/L, Liquid, ChemigationCucurbit/ Brassica/Fruiting/ Dry bulbVegetablesSL/ G: 37.6 PF 5: 0.04386 lb ai/ A350 A0.114530.00133 4,5000.051SLN Vegetables 9 lb ai/A 0.171350.002 3,0000.034M/L, Liquid, GroundboomApplicationGolf Course 12.5 lb ai/A 40 A 0.02722200.000317 19,0000.21Cucurbit/ Brassica/Fruiting/ Dry bulbVegetables6 lb ai/A80 A0.02612300.000304 20,0000.22SLN Vegetables 9 lb ai/A 0.03931500.000457 13,0000.14ApplicatorApplying Sprays viaGroundboom EquipmentGolf CourseSL/G: 16.1 PF 5: 0.06812.5 lb ai/A 40 A 0.01175100.000493 12,0000.45Cucurbit/ Brassica/Fruiting/ Dry bulbVegetables6 lb ai/A80 A0.01125400.000472 13,0000.48SLN Vegetables 9 lb ai/A 0.01683600.00071 8,5000.32Applying Granule viaTractorGolf Course SL/G: 7.2 PF 5: 0.24 16 lb ai/A 40 A 0.006689000.002232,7000.45Mixer/Loader/ApplicatorM/L/A, Liquid, HandgunGolf Course/ Lawn SL/ G: 880 PF 5: 0.38 12.5 lb ai/A 5 A 0.0797750.000345 17,0000.074Field Crop SL/G: 390 PF 5: 0.780.16 lbai/gal1000 gal 0.0904660.00181 3,3000.062L/A, Granule, RotarySpreaderLawnDL/G: 130 PF 5: 212.5 lb ai/A5 A0.01185100.00181 3,3000.35Golf Course 16 lb ai/A 0.01514000.002322,600 0.271 Based on the “Occupational Pesticide HandlerUnit Exposure Surrogate Reference Table”(March 2013); Level of mitigation: SL/G=Single layer clothing and gloves; DL/G = Double layer clothingand gloves; PF 5 = respirator with protection factor of 5; PF 10= respirator with protection factor of 10; EC = engineering controls.2Based on registered labels (see Table 3.3).3 Exposure Science Advisory Council Policy #9.1.4 Dermal Dose = Dermal Unit Exposure (μg/lb ai) × Conversion Factor (0.001 mg/μg) × Application Rate (lb ai/acre orgal) × Area Treated or Amount Handled(A or gal/day) × DAF (10%) ÷ BW (69kg).5 Dermal MOE = Dermal NOAEL (6 mg/kg/day) ÷ DermalDose (mg/kg/day).6 Inhalation Dose = Inhalation Unit Exposure (μg/lb ai) × Conversion Factor (0.001 mg/μg) × Application Rate (lb ai/acre or gal) × Area Treated or Amount Handled (A or gal/day) ÷ BW (69 kg).7 Inhalation MOE = Inhalation NOAEL (6 mg/kg/day) ÷ InhalationDose (mg/kg/day).8 ARI = Aggregate Risk Index = 1÷ [(Dermal LOC ÷ Dermal MOE)+ (Inhalation LOC ÷ Inhalation MOE)].Bensulide Human Health Risk Assessment DP No. D428598Page55of97Table 8.1.2. Occupational Handler Non-Cancer Exposure and Risk Estimates for Bensulide (with additional level of PPE).Exposure ScenarioCrop or TargetDermal UnitExposure(μg/lb ai)1Inhalation UnitExposure(μg/lb ai)1MaximumApplicationRate2Area Treated orAmountHandled Daily3SL/G + PF 5DL/G + PF 5SL/G + PF 10DL/G + PF 10ECARI4Mixer/LoaderM/L, Granule, TractorApplicationGolf CourseSL/G: 6.9DL/G: 3.4EC: 8.6PF 5: 0.34PF 10: 0.17EC: 0.08316 lb ai/A 40 A0.380.48(current PPE)0.54 0.76 0.58M/L, Liquid,ChemigationCucurbit/ Brassica/Fruiting/ Dry bulbVegetablesSL/ G: 37.6DL/ G: 29.1EC: 8.6PF 5: 0.0438PF 10: 0.0219EC: 0.0836 lb ai/ A350 A0.051(current PPE)0.065 0.052 0.066 0.18SLN Vegetable 9 lb ai/A0.034(current PPE)0.043 0.034 0.044 0.12M/L, Liquid,GroundboomApplicationGolf Course 12.5 lb ai/A 40 A0.21(current PPE)0.27 0.22 0.27 0.75Cucurbit/ Brassica/Fruiting/ Dry bulbVegetables6 lb ai/A80 A0.22(current PPE)0.29 0.23 0.29 0.77SLN Vegetables 9 lb ai/A0.14(current PPE)0.19 0.15 0.2 0.52ApplicatorApplying Sprays viaGroundboomEquipmentGolf CourseSL/G: 16.1DL/ G: 12.6EC: 5.1PF 5: 0.068PF 10: 0.034EC: 0.04312.5 lb ai/A 40 A0.45(current PPE)0.57 0.48 0.611.3Cucurbit/ Brassica/Fruiting/ Dry bulbVegetables6 lb ai/A200 A0.48(current PPE)0.59 0.51 0.631.4SLN Vegetables 9 lb ai/A0.32(current PPE)0.4 0.34 0.43 0.88Applying Granule viaTractorGolf CourseSL/G: 7.2DL/ G: 4.2EC: 2PF 5: 0.24PF 10: 0.12EC: 0.2216 lb ai/A 40 A0.45(current PPE)0.56 0.6 0.82 0.74Mixer/Loader/ApplicatorM/L/A, Liquid, HandgunGolf Course/ LawnSL/ G: 880DL/G: 450PF 5: 0.38PF 10: 0.1912.5 lb ai/A 5 A0.074(current PPE)0.15 0.075 0.15NAField CropSL/G: 390DL/G: 290PF 5: 0.78PF 10: 0.390.16 lb ai/gal 1000 gal0.062(current PPE)0.082 0.064 0.086NAL/A, Granule, RotarySpreaderLawnSL/G: 240DL/G: 130PF 5: 2PF 10: 112.5 lb ai/A5 A0.220.35(current PPE)0.25 0.41NAGolf Course 16 lb ai/A0.180.27(current PPE)0.2 0.33NA1 Based on the “Occupational Pesticide HandlerUnit Exposure Surrogate Reference Table”(March 2013); Level of mitigation: SL/G=Single layer clothing and gloves; DL/G = Double layer clothingand gloves; PF 5 = respirator with protection factor of 5; PF 10= respirator with protection factor of 10; EC = engineering controls.Bensulide Human Health Risk Assessment DP No. D428598Page56of972Based on registered labels (see Table 3.3).3 Exposure Science Advisory Council Policy #9.1.4 ARI = Aggregate Risk Index = 1÷ [(Dermal LOC ÷ Dermal MOE)+ (Inhalation LOC ÷ Inhalation MOE)].Bensulide Human Health Risk Assessment DP No. D428598

Page 57 of 97 9.2 Steady-State Post-Application Risk

HED uses the term post-application to describe exposures that occur when individuals are present in an environment that has been previously treated with a pe sticide (also referred to as reentry exposure). Such exposures may occur when workers enter previously treated areas to perform job functions, including ac tivities related to crop producti on, such as scouting for pests or harvesting. Post-application e xposure levels vary over time and depend on such things as the type of activity, the nature of the crop or target that was trea ted, the type of pesticide application, and the chemical’s degradation properties. In addition, the timing of pesticide applications, relative to harvest activities, can greatly reduce the potential for post-application exposure.

9.2.1 Dermal Post-Application Risk

Bensulide is registered for us e on golf course turf and on vegetable crops. A dermal postapplication assessment has been conducted for th e golf course turf use. However, since bensulide is applied to vegetabl es as a preplant or preemerge nce application only, occupational post-application dermal exposures are not anticipate d for these uses. There is a low potential for occupational post-application exposure when pre- emergent herbicides are used. Bensulide is applied to the soil directly and is soil incorpor ated well before the crops are mature. The timing of the application of bensulid e can greatly reduce the potential for post-application exposure. Minimal exposure during harvesting or any othe r late season activities is expected since bensulide is applied pre-emergent. Theref ore, HED does not requi re a post-application occupational exposure assessment (HED Exposure Science Advisory Council Policy No. 008).

Occupational Post-application Dermal Exposure Data and Assumptions

A series of assumptions and exposure factors serv ed as the basis for completing the occupational post-application risk assessments for the golf course use. Each assumption and factor is detailed

below on an individual basis.

Exposure Duration: For bensulide, an exposure profil e consistent with steady-state exposure is expected.

Transfer Coefficients: It is the policy of HED to use the best available data to assess postapplication exposure. Sources of generic post-application data, us ed as surrogate data in the absence of chemical-specific data, are derived from ARTF exposure monitoring studies, and, as proprietary data, are subject to the data protection provisions of FIFRA. The standard values recommended for use in predicting post-applicati on exposure that are used in this assessment, known as “transfer coefficients”, ar e presented in the ExpoSAC Policy 3 13 ” which, along with

additional information about the ARTF da ta, can be found at the Agency website 14 . Table 9.2.1.1 provides a summary of the antic ipated post-application activit ies and associated transfer coefficients for the proposed crops/use sites.

13 Available: http://www2.epa.gov/sites/production/files/2015 -08/documents/exposac-policy-3-march2013.pdf

14 Available: http://www2.epa.gov/pesticide-scie nce-and-assessing-pesticide-risk s/occupational-pesticide-postapplication-exposureBensulide Human Health Risk Assessment DP No. D428598

Page 58 of 97 Table 9.2.1.1. Anticipated Po st-Application Activities and Dermal Transfer Coefficients.

Proposed Crops Policy Crop Group Category Crop Height Foliage Density Transfer

Coefficients

(cm 2 /hr ) Activities

Golf Course Turf Low Full 3700 Maintenance

Application Rate: Application rates are listed in Table 3.3.

Exposure Time: The average occupational workda y is assumed to be 8 hours.

Turf Transferable Residues: Chemical-specific TTR data are available for the liquid formulation of bensulide. See Section 6.2 for a description of the TTR data. The data include measurements

on bensulide and the oxon. Due to the differences in the dissipation of bensulide and the oxon, residues of the oxon were adjusted by the toxi city adjustment factor (TAF; oxon residue, ug/cm 2
* 50X TAF), and total residues (b ensulide + adjusted oxon) were used to determine the risk resulting from exposures following bensulide app lications. Since no data are available for the granular formulation, the liquid fo rmulation residue data were us ed as a surrogate. As noted above, this is considered a health protective approach since, in general, granular formulations tend to result in lower percen t transfer from turf than do liquid formulations (e.g., the 2012 Residential SOP turf default per cent transfer factor is 1% for liquids and 0.2% for granulars).

Body Weight: For adults, when an endpoint is not sex-specific (i.e., the endpoints are based on developmental or fetal effects) a body weight of 80 kg is typically used in risk assessment; however, in this case, a female-specific body wei ght of 69 kg was used. While the endpoint of concern, RBC AChE inhibition, is not sex-specific, the female-specific body weight was used to protect for pregnant women due to uncertainty in the human dose-response relationship for neurodevelopmental eff ects (See Section 4.4).

Occupational Post-application Non-Cancer Derm al Exposure and Risk Estimate Equations The algorithms used to estimat e non-cancer exposure and dose fo r occupational post-application workers can be found in the occupational and residential exposure (ORE) memo for bensulide (D428877, A. Gavalek and K. Lowe, 03/03/2016).

Occupational Post-application Non- Cancer Dermal Risk Estimates Occupational post-applicati on risks were estimated for workers; risk estimates were of concern until 5 days after treatment (DAT 5). See tables 9.2.1.2 (for liquid formulations) and 9.2.1.3 (for granular formulations) below for a summary of the occupational post-application risk estimates.Bensulide Human Health Risk Assessment DP No. D428598

Page 59 of 97 Table 9.2.1.2. Occupational Post-application Non-Cancer Exposure and Risk Estimates for Bensulide + Oxon (with 50X TAF) (Liquid Formulations).

Crop/Site Activities Transfer Coefficient (cm 2 /hr) DAT TTR 1 Dermal Dose (mg/kg/day) 2 MOE (LOC = 1000) 3

Golf Course Maintenance 3700 0 0.475 0.0204 290

1 0.351 0.0151 400

2 0.259 0.0111 540

3 0.192 0.0082 730

4 0.141 0.0061 990

5 0.105 0.00448 1,300

1 TTR = Data from MRID 44799001. Total TTR, ug/cm 2 = [ (oxon residue, ug/cm 2 ) * 50 X TAF] + [bensulide residue, ug/cm 2 ). 2 Daily Dermal Dose = [DFR (μg/cm 2 ) × Transfer Coefficient × 0.001 mg/μg × 8 hrs/day × dermal absorption (10%)]  BW (69 kg). 3 MOE = POD (6 mg/kg/day) / Daily Dermal Dose.

Table 9.2.1.3. Occupational Post-application Non-Cancer Exposure and Risk Estimates for Bensulide + Oxon (with 50X TAF) (Solid Formulations).

Crop/Site Activities Transfer Coefficient (cm 2 /hr) DAT TTR 1 Dermal Dose (mg/kg/day) 2 MOE (LOC = 1000) 3

Golf Course Maintenance 3700 0 0.6083 0.026097 230

1 0.4493 0.019276 310

2 0.3319 0.014238 420

3 0.2452 0.010517 570

4 0.181 0.00777 770

5 0.134 0.00574 1,000

1 TTR = Default assumption that 0.2% of a pplication rate available as TTR on day 0. Dissipation rate a nd oxon conversion data from MRID

44799001. Total TTR, ug/cm 2 = [ (oxon residue, ug/cm 2 ) * 50 X TAF] + [bensulide residue, ug/cm 2 ). 2 Daily Dermal Dose = [DFR (μg/cm 2 ) × Transfer Coefficient × 0.001 mg/μg × 8 hrs/day × dermal absorption (10%)]  BW (69 kg). 3 MOE = POD (6 mg/kg/day) / Daily Dermal Dose.

Restricted Entry Interval

Bensulide is classified as Toxi city Category III via the dermal route, Toxicity Category IV for dermal irritation, and Toxicity Cate gory III for eye irritation. It is not a skin sensitizer. Under 40 CFR 156.208 (c) (2), ai’s classi fied as Acute III or IV for acute dermal, eye irritation and primary skin irritation are assi gned a 12-hour REI. However, st eady-state post-application risk estimates were a concern up to Day 5 for golf cour se maintenance activities. Therefore, HED is recommending that the REI for gol f courses be revised on the labe l to address those concerns.

9.2.2 Inhalation Post-Application Risk

There are multiple potential sources of post-app lication inhalation exposure to individuals performing post-applicati on activities in previously treated fields. These potential sources

include volatilization of pesticides and resuspension of dusts and/or particulat es that contain pesticides. The Agency sought expert advice an d input on issues relate d to volatilization of pesticides from its Federal Insecticide, Fungicide , and Rodenticide Act Scie ntific Advisory Panel (SAP) in December 2009, and received th e SAP’s final report on March 2, 2010Bensulide Human Health Risk Assessment DP No. D428598

Page 60 of 97 (http://www.regulations.gov/#!documen tDetail;D=EPA-HQ-OPP-2009-0687-0037). The Agency has evaluated the SAP report and has de veloped a Volatilization Screening Tool and a subsequent Volatilization Screening Analysis (http://www.regulations.gov/#! docketDetail;D=EPA-HQ-OPP-2014- 0219). During Registration Review, the Agency will u tilize this analysis to determine if da ta (i.e., flux studies, route-specific inhalation toxicological studi es) or further analysis is required for bensulide.

In addition, the Agency is continuing to eval uate the available post- application inhalation exposure data generated by the Ag ricultural Reentry Task Force. Given these two efforts, the Agency will continue to identify the need for and, subsequently, the way to incorporate occupational post-application inhalation expos ure into the Agency's risk assessments.

10.0 Public Health and Pesticide Epidemiology Data
Adapted from: S. Recore, D428879, 08/10/2015

IDS records incidents resulting in higher severity outcomes in more detail, in a module called the Main IDS module. This system stores incident data for death, major and moderate incidents, and

it includes more details about the location, date and nature of the incident. Main IDS incidents involving only one pesticide are considered to provide more certain information about the potential effects of exposure from the pestic ide. The less severe human incidents (minor, unknown, or no effects outcomes) are reported by registrants as counts called aggregate summaries and are recorded in a separate module called Aggregate IDS. The SENSORPesticides database covers 11 states from 1998-2010, although reporting va ries from state to state. Cases of pesticide-rela ted illnesses are ascertained fr om a variety of sources. Although both occupational and non-occupational incident s are included in the database, SENSORPesticides focuses on occupational pesticide incidents, and is of particular value in providing that information. For this evaluation, both the ID S and SENSOR database were consulted for pesticide incident data on the active ingred ient bensulide (PC Code: 009801). In addition, we sought information from the Agricultural He alth Study (AHS); howev er, bensulide is not

included in the AHS.

Bensulide was previously reviewed in 1998 (J . Blondell and M. Spann, 2/9/1998, D239353). At the time, there were two incidents reported fo r bensulide in IDS from 1992 – February 1998. Upon review of these incidents, no recommenda tions were made and it was concluded that, “Very few illness cases have been reported due to bensulide and none have been confirmed.” The current IDS analysis from January 1, 2010 through August 25, 2015, shows 2 moderate severity incident reported i nvolving bensulide in Main IDS a nd 5 minor severity incidents reported to Aggregate IDS. Th e query of SENSOR-Pesticides 1998- 2011 identified a total of 38 cases involving (pc code 009801). Of these 38 cases, 17 cases, stemming from seven events, involve a single ai and were revi ewed further. Fourteen cases were low in severity and three cases were moderate in severity. Sixteen cases were occupational exposure. A total of 14 of the single ai cases reports were cau sed by two spray drift events. i

i SENSOR-Pesticides defines drift as “off-target movement of pesticide” which includes cases of volatilization.Bensulide Human Health Risk Assessment DP No. D428598

Page 61 of 97 Conclusion: Based on the low frequency of incident s involving bensulide reported to both IDS and SENSOR-Pesticides, there does not appear to be a concern at this time. The Agency will

continue to monitor the incident information a nd if a concern is triggered, additional analysis

will be conducted.

11.0 References

Bensulide. Acute and Steady St ate Probabilistic Aggregate Di etary (Food Only, and Food and Drinking Water) Exposure and Risk Assessments for Registration Review Risk Assessment; I. Negrón-Encarnación; D428878; 03/02/2016.

Bensulide. Summary of Analy tical Chemistry and Residue Data in Support of Registration Review; I. Negrón-Enca rnación; D429307; 03/02/2016.

Bensulide. Occupational and Residential E xposure Assessment in Support of Registration Review; A. Gavalek and K. Lowe; D428877; 03/03/2016.

HASPOC Memo; Van Alstine, 2013; TXR # 0056738.

HASPOC Memo; Leshin, 2015, TXR # 0057280.

Bouchard MF, Chevrier J, Harley KG, Kogut K, Vedar M, Calderon N, et al. Prenatal Exposure to Organophosphate Pesticides and IQ in 7-Y ear-Old Children. Environ Health Perspectives. 2011;119:1189-1195.

Engel SM, Berkowitz GS, Barr DB, Teitelbaum SL , Siskind J, Meisel SJ, Wetmur JG, Wolff MS. Prenatal Organophosphate Metabolite and Or ganochlorine Levels and Performance on the

Brazelton Neonatal Behavioral Assessment Scale in a Multiethnic Pregnancy Cohort. American Journal of Epidemiology. 2007;165:1397-1404.

Engel SM, Wetmur J, Chen J, Zhu C, Barr DB, Canfield RL, Wolff MS. Prenatal Exposure to Organophosphates, Paraoxonase 1, and Cognitive Development in Childhood. Environmental Health Perspectiv es. 2011;119:1182-1188.

Eskenazi B, Harley K, Bradman A, Weltzie n E, Jewell NP, Barr DB, Furlong CE, Holland NT. Association of in Utero Organophosphate Pestic ide Exposure and Fetal Growth and Length of Gestation in an Agricultural Population. Environmental Health Perspectives. 2004;115:792–798.

Eskenazi B, Marks AR, Bradman A, Harley K, Barr DB, Johnson C, Morga N, Jewell NP. Organophosphate Pesticide Exposure and Neur odevelopment in Young Mexican-American

Children. Environmental Health Perspectives. 2007;115:792–798.

FIFRA Scientific Advisory Panel. (2012). Tran smittal of the Meeting Minutes from the FIFRA Scientific Advisory Panel Meeting of April 10-12, 2012. FIFRA Scientific Advisory Panel, Office of Science Coordination and Policy, O ffice of Prevention, Pesticides and ToxicBensulide Human Health Risk Assessment DP No. D428598

Page 62 of 97 Substances, U.S. Environmental Protect ion Agency. Washington, DC. Available: http://www.epa.gov/scipoly/sap/ meetings/2012/041012meeting.htmll

Fortenberry, GZ, Meeker, JD, Sánchez, BN, Barr, DB, Panuwet, P, Bellinger, D, Schnaas, L, Solano-González, M, Ettingera, AS, Hernandez- Avila, M, Hu, H, Tellez-Rojoj, MM. Urinary 3,5,6-trichloro-2-pyridinol (TCPY) in pregnant women from Mexico City: Distribution, temporal variability, and relations hip with child attention and hypera ctivity. Internati onal Journal of Hygiene and Environmental Health 217 (2014): 405–412.

Fortenberry, GZ, Meeker, JD, Sánchez, BN, Barr, DB, Peterson, K, Bellinger, D, Schnaas, L, Solano-González, M, Ettinger, AS, Hernandez-Av ila, M, Hu, H, Tellez-Rojoj, MM. Paraoxonase I polymorphisms and attention/hyperactivity in sc hool-age children from Mexico City, Mexico. (2014a.) Environmental Research 132:342–349.

Furlong, Melissa A., Engel, Stephanie M., Boyd Barr, Dana, Wolff, Mary S. Prenatal exposure to organophosphate pesticides and reciprocal so cial behavior in ch ildhood. 2014. Environment

International 70:125-131.

Guodong, Ding, Pei, Wang, Ying, Tian, Jun, Zhang, Yu, Gao, Xiaojin, Wang, Rong, Shi, Guoquan, Wang, and Xiaoming, Shen. Orga nophosphate Pesticide Exposure and Neurodevelopment in Young Shanghai Childre n. Environmental Science and Technology 46:2911-2917, 2012.

Oulhote, Youssef and Bouchard, Maryse F. Urinary Metabolites of Organophosphate and Pyrethroid Pesticides and Beha vioral Problems in Canadian Children. Environmental Health Perspectives. 121:1378-1384 (2013).

Rauh VA, Garfinkel R, Perera FP, Andrews HF , Hoepner L, Barr DB, Whitehead R, Tang D, Whyatt RW. Impact of Prenatal Chlorpyrifos Exposure on Neurodevelopment in the First 3 Years of Life Among Inner-City Chil dren. Pediatrics. 2006;18(6): 1835-1859.

Rauh V, Arunajadai S, Horton M, Perera F, Ho epner L, Barr DB, et al. 2011. Seven-Year Neurodevelopmental Scores and Prenatal Expos ure to Chlorpyrifos, a Common Agricultural

Pesticide. Environmental Hea lth Perspectives. 2011;119:1196-1201.

Shelton, Janie F., Geraghty, Estella M., Tancre di, Daniel J., Delwiche, Lora D., Schmidt, Rebecca J., Ritz, Beate, Hansen, Robin L., a nd Hertz-Picciotto, Irva. Neurodevelopmental disorders and prenatal residential proximity to agricultural pestic ides: The CHARGE Study. Environmental Health Perspectives 122:1103–1109, 2014.

U.S. Environmental Protection Agency. (2008). Science Issue Paper: Chlorpyrifos Hazard and Dose Response Characterization. http://www.epa.gov/scipoly/sa p/meetings/2008/091608_mtg.htmBensulide Human Health Risk Assessment DP No. D428598

Page 63 of 97 U.S. Environmental Protection Agency. (2012). Dr aft Issue Paper: Scien tific Issues Concerning Health Effects of Chlorpyrifos. http://www. regulations.gov/#!documentDetail;D=EPA-HQ-OPP2012-0040-0002

Young JG, Eskenazi B, Gladstone EA, Bradman A, Pedersen L, Johnson C, Barr DB, Furlong CE, Holland NT. Association Between In Ut ero Organophosphate Pesticide Exposure and Abnormal Reflexes in Neonates. NeuroToxicology. 2005;26:199–209.

Zhang, Ying, Han, Song, Liang, Duohong, Shi, Xi nzhu, Wang, Fengzhi, Wei Liu, Zhang, Li, Chen, Lixin, Gu, Yingzi, Tia n, Ying. Prenatal exposure to organophosphate pesticides and neurobehavioral development of neonates: A bi rth cohort study in Shenyang, China. PlosOne 47:80–85, 2014.Bensulide Human Health Risk Assessment DP No. D428598

Page 64 of 97 Appendix A. Toxicology Prof ile and Executive Summaries

A.1 Toxicology Data Requirements
The requirements (40 CFR 158.340) for food use for bensulide are in Table 1. Use of the new guideline numbers does not imply that the new (1998) guideline protocols were used.

Study Technical Required Satisfied 870.1100 Acute Oral Toxicity ....................................................... 870.1200 Acute Dermal Toxicity ..................................................

870.1300 Acute In halation Toxicity ..............................................

870.2400 Acut e Eye Irr itation

....................................................... 870.2500 Acute Dermal Irritation .................................................

870.2600 Skin Sensitiza tion .......................................................... yes

yes

yes

yes

yes

yes yes

yes

yes

yes

yes

yes 870.3100 90-Day Oral Toxicity in Rodents .................................. 870.3150 90-Day Oral Toxicity in Non-rodents ............................

870.3200 21/28-Da y Dermal Toxicity ........................................... 870.3250 90-Day Dermal Toxicity ................................................ 870.3465 90-Day Inhalation To xicity ........................................... yes

yes

yes

no

yes yes

yes

yes

-

no 870.3700a Prenatal Developmen tal Toxicity in Rodents ................ 870.3700b Prenatal Developmenta l Toxicity in Non-rodents ......... 870.3800 Reproductio n and Fertility Effects ................................. yes

yes

yes yes

yes

yes
870.4100a Chronic Toxi city in Ro dents ..........................................

870.4100b Chronic Toxic ity in Non-rodents ................................... 870.4200a Carcinogen icity in Rats .................................................. 870.4200b Carcinogeni city in Mice ................................................ yes

yes

yes

yes yes

yes

yes

yes 870.5100 Mutagenicity—Bacterial Reverse Mutation Test .......... 870.5300 Mutagenicity—Mammalian Cell Gene Mutation Test .. 870.5375 Mutagenicity—Struc tural Chromosomal Aberrations ... 870.5385 Mutagenicity—Mammalian Bone Marrow Chromosomal Aberration Test 870.5395 Mutagenicity—Mammalian Erythrocyte Micronucleus Test yes

yes

yes

yes

yes yes

yes

yes

yes a

yes 870.6100 28-Day Delaye d Neurotoxicity in Hens......................... 870.6200a Acute Neurotoxicity Screening Battery in Rats ............. 870.6200b 90-Day Neurotoxicity Screening Battery in Rats .......... 870.6300 Developm ental Neurot oxicity ........................................ yes

yes

yes

yes yes

yes

yes b

yes b

870.7800 Immunotoxicity

Special Studies Comparative Cholineste rase in Rats ........................... yes

yes yes c

yes

a Although there were no guideline 870.5385 studies subm itted, there are mutagenicity studies which evaluate both somatic and germinal cells, which is consider ed sufficient to satisfy CFR requirements. b Study not required by HASPOC (Leshin, 2015, TXR # 0057280). c (van Alstine, 2013, TXR # 0056738)Bensulide Human Health Risk Assessment DP No. D428598

Page 65 of 97 A.2 Summary of OPP’s ChE Policy & Use of BMD Modeling

OPP’s ChE policy (USEPA, 2000 15 ) describes the manner in which ChE data are used in human health risk assessment. The following text provi des a brief summary of that document to provide context to points of departure selected.

ChEI can be inhibited in the cen tral or peripheral ne rvous tissue. Measurements of AChE or ChE inhibition in peripheral tissues (e.g., liver, diaphragm, heart, lung, etc.) are rare. Experimental laboratory studies generally meas ure brain (central) and blood (plasma and RBC) ChE. Blood measures do not represent the targ et tissue, but are instead used as surrogate measures for peripheral toxicity in studies with laboratory an imals or for peripheral and/or central toxicity in humans. In addition, RBC measures represent AChE, whereas plasma measures are predominately butyryl-ChE (BuChE). RBC AChE data are expected to provide a better representation of the inhibition of AChE in target tissues. As part of the dose response assessment, evaluations of neurobe havior and clinical signs are performed to consider the dose response linkage between Ch EI and apical outcomes.

Refinements to OPP’s use of ChE data have come in the implementation of BMD approaches in dose response assessment. Beginning with the OP CRA, OPP has incr eased its use of BMD modeling to derive PODs for AChE inhibi ting compounds. Most often, the decreasing exponential empirical model has been used.

OPP does have not a defined benchmark response (BMR) for OPs. However, the 10% level has been used in the majority of dose response analyses conducte d to date. This 10% level represents a 10% reduction in AC hE activity (i.e., inhibition) compared to background (i.e., controls). Specifically, the BMD 10 is the estimated dose where ChE is inhibited by 10% compared to background. The BMDL 10 is the lower confidence bound on the BMD 10

.

The use of the 10% BMR is derived from a combination of statis tical and biological considerations. A power analysis was conducte d by the Office of Research and Development (ORD) on over 100 brain AChE datasets across mo re than 25 OPs as part of the OP CRA (USEPA, 2002). This analysis demonstrated that 10% is a level that can be reliably measured in the majority of rat toxicity studi es. In addition, the 10% level is generally at or near the limit of sensitivity for discerning a statistically significant decrease in ChE activity in the brain compartment and is a response le vel close to the background brain ChE level. With respect to biological considerations, a change in 10% brai n ChEI is protective for downstream clinical signs and apical neurotoxic outcomes. With re spect to RBC ChEI, these data tend to be more variable than brain AChE data. OPP begins its BMD analyses using the 10% BMR for RBC ChEI, but BMRs up to 20% could be considered on a case by case basis as long as such PODs are protective for brain ChEI, potential peripheral inhibition, and clinical signs of neurotoxicity.

15 USEPA (2000) Office of Pesticide Programs, US Environmental Protection Agency, Washington DC 20460. August 18, 2000 Office of Pesticide Programs Science Policy of Th e Use of Data on Cholinesterase Inhibition for Risk Assessments of Organophosphorous and Carbamate Pesticides.Bensulide Human Health Risk Assessment DP No. D428598

Page 66 of 97 The results of the BMD modeling for the bensulide are as follows:

Table A.2.1. Results of BMD Modeling (mg/kg) fo r Brain and RBC ChE Data on Bensulide, Acute Oral Dosing Studies in Rats.

Test Age

Sex Brain

BMD 10 Brain

BMDL 10 RBC

BMD 10 RBC

BMDL 10 MRID 49433502

Acute CCA Adult

Male 79.94 63.10 79.11 55.92

MRID 49433502

Acute CCA Adult

Female 46.39 36.88 27.21 21.53

MRID 49433502

Acute CCA PND 11

Male 26.04 16.67 17.74 11.61

MRID 49433502

Acute CCA PND 11

Female 28.90 21.30 16.23 11.24

MRID 43195901 Acute Neurotoxicity Adult

Male 149.72 95.46 QF

MRID 43195901 Acute Neurotoxicity Adult

Female QF 37.29 30.30

CCA = Comparative Cholinesterase Assay QF = Questionable fit, all statistical tests of fit were no t passed and/or high variance was observed in the dose

groupsBensulide Human Health Risk Assessment DP No. D428598

Page 67 of 97 Table A.2.2. Results of BMD Modeling (mg/kg/d ay) for Brain and RBC ChE Data on Bensulide, Repeated Oral Dosing Studies in Rats.

Test (Dosing Days) Age

Sex Brain

BMD 10 Brain

BMDL 10 RBC

BMD 10 RBC

BMDL 10 MRID 44161101 Chronic/Carc, 103W Adult

Male NE NE

MRID 44161101 Chronic/Carc, 103W Adult

Female NE 11.68 7.83

MRID 44161101 Chronic/Carc, 77W Adult

Male NE NE

MRID 44161101 Chronic/Carc, 77W Adult

Female NE 6.63 4.53

MRID 44161101 Chronic/Carc, 51W Adult

Male 29.58 16.20 NF

MRID 44161101 Chronic/Carc, 51W Adult

Female 26.26 14.97 4.19 3.77

MRID 44161101 Chronic/Carc, 25W Adult

Male 25.68 18.15 4.51 2.77

MRID 44161101 Chronic/Carc, 25W Adult

Female NF 7.26 5.16

MRID 43919601
Subchronic rat, 13W Adult

Male NE NE

MRID 43919601
Subchronic rat, 13W Adult

Female NE 9.53 7.19

MRID 49454001 Gestational CCA, 13D Dam 23.52 21.54 12.01 10.03

MRID 49454001 Gestational CCA, 13D Fetus

Male 27.08 21.92 22.34 17.19

MRID 49454001 Gestational CCA, 13D Fetus

Female 31.37 24.38 21.82 17.40

MRID 49466201 Repeated-Dose CCA, 10D Adult

Male NT NT

MRID 49466201 Repeated-Dose CCA, 10D Adult

Female 31.04 25.87 18.66 15.92

MRID 49466201 Repeated-Dose CCA, 10D PND 11

Male 19.60 15.67 7.91 5.92

MRID 49466201 Repeated-Dose CCA, 10D PND 11

Female 17.30 12.87 12.30 9.05

MRID 43948701
2 gen repro F0

Male QF 197.77 132.68

MRID 43948701
2 gen repro F0

Female 312.99 83.08 114.32 91.53

MRID 43948701
2 gen repro F1

Male QF QF

MRID 43948701
2 gen repro F1

Female 466.83 214.75 QF

CCA = comparative cholinesterase assay

NF = No model fit the data wellBensulide Human Health Risk Assessment DP No. D428598

Page 68 of 97 NE = Not evaluated

NT = Not tested NDR = No dose response found upon analysis

NA = Result considered not accurate

QF = Questionable fit, all statistical tests of fit were not passed and/or high variance was observed in the dose groups

Tox = Toxicity Carc = Carcinogenicity

Chronic dog: no apparent dose response for male and female brain ChEI, and no fit due to too

much variance for male and female RBC ChEI.

Dermal toxicity: no apparent dose response (did not mode l) for both sexes and both brain and

RBC ChEI. The LOAEL was not establishe d in MRID 42162002 (NOAEL = 1000 mg/kg/day). The LOAEL was 500 mg/kg/day in MRIDs 44801101 and 44809401 based on decreased plasma and brain ChE (no RBC ChEI), and the NOAEL = 50 mg/kg/day.

Bensulide Toxicity Profiles follow:

Table A.2.3. Acute Toxicity Profile – Bensulide

Guideline

No. Study Type MRID # Results Toxicity Category

870.1100 Acute oral [rat] 00097921

92005011 LD 50 = 360 mg/kg (M)

LD 50 = 270 mg/kg (F) II

870.1200 Acute dermal [rat] 41597501 LD 50 ≥ 2000 mg/kg III 870.1200 Acute dermal [rabbit] 00097921 LD50 > 5000 mg/kg IV 870.1300 Acute inhalation [rat] 41646201 LC 50 > 1.75 mg/L III 870.2400 Acute eye irritation [rabbit] 41597502 mild irritant III

870.2500 Acute dermal irritation [rabbit] 00097921

92005012 mild irritant IV

870.2600 Dermal sensitization [guinea pig] 00160075 not a sensitizer NA

Table A.2.4. Subchronic, Chronic, and Other Toxicity Profile – Bensulide

Guideline No./Study Type MRID No. (year)/

TXR #/ Classification

/Doses Results

870.3100a 90-Day oral toxicity

rodents - rat 43919601 (1992)

TXR 0012289 Acceptable, guideline
0, 5, 15, 45, or 100 mg/kg/day NOAEL = 5 mg/kg/day

LOAEL = 15 mg/kg/day based on decreased plasma ChE in

both sexes and brain ChE in males

At 45 and 100 mg/kg/day, decreased RBC and brain ChE in

both sexes and liver vacuolation in males. At 100 mg/kg/day, increased ALT in both sexes, fatty microvesicles in males, and liver weight in males

870.3100b 90-Day oral toxicity

rodents - mouse 44161104 (1993)

TXR 0012289 Acceptable, guideline
0, 30, 100, 300, or 1000 mg/kg/day NOAEL = 300 mg/kg/day LOAEL = 1000 mg/kg/day based on decreased body weight in males, increased liver weight, liver lobulation hepatocyte hypertrophy in both sexes, liver enlargement in males, decreased ovarian and spleen weights in femalesBensulide Human Health Risk Assessment DP No. D428598

Page 69 of 97 Table A.2.4. Subchronic, Chronic, and Other Toxicity Profile – Bensulide

Guideline No./Study Type MRID No. (year)/

TXR #/ Classification

/Doses Results

870.3150b 90-Day oral toxicity non-rodents - dogs 44052703 (2016)

TXR 0057338 Acceptable, guideline
0, 1, 3, 10, or 30 mg/kg/day NOAEL = 10 mg/kg/day LOAEL = 30 mg/kg/day based conservatively on increased liver weight, increased incidence of liver lipid deposits, and increased activated partial thromboplastin times

870.3200 21-Day dermal toxicity with parent - rat 42162002 (1991)

TXR 0009325 Acceptable, guideline
0, 10, 100, or 1000 mg/kg/day NOAEL ≥ 1000 mg/kg/day

LOAEL was not established

870.3200 21-Day dermal toxicity with parent - rat 44801101 and 44809401 (1999)

TXR 0013532Acceptable, nonguideline
0, 30, 50, or 500 mg/kg/day (6 h/d, 21 d) NOAEL = 50 mg/kg/day LOAEL = 500 mg/kg/day based on decreased plasma and

brain ChE

Note: No effect was noted on RBC ChE in either sex at any time point.

870.3700a Prenatal developmental

- rat 00146585 (1985) 92005018 (1990)

TXR 0012289 Acceptable, guideline
0, 5.5, 23.0, or 95.0 mg/kg/day Maternal NOAEL = 5.5 mg/kg/day Maternal LOAEL = 23.0 mg/kg/day based on decreased plasma ChE In the 95.0 mg/kg/day dams, tremor and decreased BWG, FC, whole and corrected (uteri ne wt) BW were noted.

Developmental NOAEL ≥ 95.0 mg/kg/day Developmental LOAEL was not established

870.3700b Prenatal developmental

- rabbit 00152845 (1985) 92005019 (1990)

TXR 0012289 Acceptable, guideline
0, 5, 20, or 80 mg/kg/day Maternal NOAEL = 20 mg/kg/day Maternal LOAEL = 80 mg/kg/day based on decreased body weights and weight loss during the treatment interval

Developmental NOAEL ≥ 80 mg/kg/day Developmental LOAEL was not establishedBensulide Human Health Risk Assessment DP No. D428598

Page 70 of 97 Table A.2.4. Subchronic, Chronic, and Other Toxicity Profile – Bensulide

Guideline No./Study Type MRID No. (year)/

TXR #/ Classification

/Doses Results

870.3800 Reproduction and fertility effects with

parent - rat 43948701 (1996)

TXR 0012289 Acceptable, guideline Pre-mating doses: P male: 0, 2.0, 12.3, or 68.2 mg/kg/day P female: 0, 2.3, 13.2, or 80.8 mg/kg/day F1 male: 2.3, 14.0, or 86.5 mg/kg/day F1 female: 2.6, 15.4, or 93.2 mg/kg/day Parental/Systemic NOAEL ≥ 68.2 mg/kg/day Parental/Systemic LOAEL was not established

ChE inhibition NOAEL was not established ChE inhibition LOAEL = 2.3 mg/kg/day based on plasma

ChE inhibition in the F1 males

In the mid and high dose P males and females, plasma ChE was decreased. In the high dose P males and females, RBC ChE was decreased, and brain ChE was also decreased in females. At the mid and high dose, decreased RBC ChE was noted in F1 males, and plasma ChE was decreased in F1 females. In the high dose F1 females, RBC and brain ChE were decreased. In the high dose P males and females, low fertility rates were noted.

Reproductive NOAEL ≥ 68.2 mg/kg/day Reproductive LOAEL was not established

Offspring NOAEL = 15.4 mg/kg/day Offspring LOAEL = 93.2 mg/kg/day based on reduced F2 pup

survival ChE not measured in pups.

870.4100b Chronic toxicity (1 year) - dogs 44066401 (2016)

TXR 0057338 Acceptable, guideline
M & F: 0, 0.5, 4, or 30 mg/kg/day NOAEL = 4 mg/kg/day LOAEL = 30 mg/kg/day based on the RBC cholinesterase inhibition and mild indications of hepatotoxicity (Kupffer-cell accumulation, inflammation, and fatty

870.4100b Chronic toxicity (1 year) - dogs 41112301 (1989) 92005016 (1990)

TXR 0008369 Acceptable, guideline M & F: 0, 2, 10, or 50 mg/kg/day NOAEL = 10 mg/kg/day LOAEL = 50 mg/kg/day based on increased mortality, clinical signs of toxicity, decreased body weight and food consumption, discolored liver, and several microscopic lesions (fibrosis and chronic inflammation of the thymus, erythroid/myeloid bone marrow depletion, inflammation and/or degeneration of the skeletal muscle, and liver changes)

870.4200b Carcinogenicity with parent - mice 44161105 (1996)

TXR 0012289 Acceptable, guideline
M & F: 0, 1, 50, or 200 mg/kg/day NOAEL = 1 mg/kg/day

LOAEL = 50 mg/kg/day based on decreased plasma and erythrocyte ChE in both sexes, brain ChE in females, and body weight gain in males

At 200 mg/kg/day, increased liver weight and liver pathology (clear cell foci, hepatocyte pigmentation, Kupffer sell pigmentation, and atypia) Carcinogenic potential is considered negative.Bensulide Human Health Risk Assessment DP No. D428598

Page 71 of 97 Table A.2.4. Subchronic, Chronic, and Other Toxicity Profile – Bensulide

Guideline No./Study Type MRID No. (year)/

TXR #/ Classification

/Doses Results

870.4300

Combined chronic toxicity/Carcinogenicity

- rats 43919602 (1995) 44161101 (1996)

TXR 0012289 Acceptable, guideline
M & F: 0, 1, 15, or 60 mg/kg/day NOAEL = 1 mg/kg/day

LOAEL = 15 mg/kg/day based on decreased plasma and erythrocytes ChE in both sexes Carcinogenic potential is considered negative.

870.5100

Bacterial reverse

mutation test with

parent 00153493 (1984) 00153495 (1984) 92005021 (1990)

TXR 0012289 Acceptable, guideline
0, 0.005, 0.014, 0.041, 0.123, 0.370, 1.111, 3.333, 10, 25, or 50 μL/plate (TA100); 0, 0.037, 0.111, 0.333, 1, or 3 μL/plate (TA98, TA1535, and TA1537) There was no evidence of indu ced mutant colonies over background in Salmonella typhimurium strains TA98, TA100, TA1535, and TA1537.

870.5300 Mouse lymphoma

cell/mammalian activation gene forward mutation assay (TK locus) with parent. 43273901 (1994)

TXR 0011409 Acceptable, guideline
0, 8,14, 16, 21, 24, 28, 32, 35, 40, or 42 μg/mL (-S9); 0, 16, 24, 28, 32, 35, 40, 42, 48, 49, or 56 μg/plate (+S9) There was no evidence of induced forward mutation at the TK

locus.

870.5375

In vitro mammalian cytogenetics (Chromosomal aberration assay in human peripheral blood) 41902601 (1990)

TXR 0009077 Unacceptable, guideline (upgradable)
0, 5, 40, 60 or 80 Bensulide was not clastogenic under conditions of the assay.

Study deficiencies included: l ack of information concerning: stability of test compound; crit eria for assessing chromosomal aberrations; level of p value used in determining statistical significance; and potential for bensulide-induced delay of cell cycle.

870.5395

In vivo mouse micronucleus 41902602 (1990) TXR 0010229;

0009077 Acceptable, guideline
M & F: 0, 250, or 400 mg/kg/day There was no significant increase in the frequency of micronucleated polychromatic er ythrocytes in bone marrow.

870.6100 Delayed neurotoxicity (Acute) - hen 43334302 (1994) 43306301 (1994)

TXR 0012289 Acceptable, guideline M: 0 or 2262 mg/kg Bensulide did not induce acute delayed neurotoxicity in the

hen at the limit dose.Bensulide Human Health Risk Assessment DP No. D428598

Page 72 of 97 Table A.2.4. Subchronic, Chronic, and Other Toxicity Profile – Bensulide

Guideline No./Study Type MRID No. (year)/

TXR #/ Classification

/Doses Results

870.6200a Acute neurotoxicity - rat 43195901 (1994)

TXR 0012289 Acceptable, guideline
M: 0, 30, 100, or 300 mg/kg
F: 0, 15, 50, or 150 NOAEL = 100 mg/kg/day LOAEL = 150 mg/kg/day based on decreased plasma, RBC, and brain ChE in females and minimal, clinical signs

consistent with ChE inhibition in females

870.6200b

Subchronic neurotoxicity screening battery - rat NA NA

870.6300 Developmental neurotoxicity study with

parent NA NA

870.7485

Metabolism and pharmacokinetics with

parent - rat 42007901 (1991) 42007902 (1991) 42007903 (1991) 42007904 (1991) 42225401 (1992)
TXR 0009491; 0012289; 0012948 Acceptable, guideline single 1 mg/kg dose, 1 mg/kg/day for 15 consecutive days, single 100 mg/kg dose, 50 mg/kg for 4 consecutive days In a rat metabolism study with 14 C-labeled bensulide, Sprague-Dawley rats received dos es of 1 mg/kg (single, low dose), 1 mg/kg × 15 days (repeated low dose), 50 mg/kg/day × 4 consecutive days (group used for metabolite isolation), and 100 mg/kg (single, high do se). Bensulide was excreted primarily in the urine, with the majority of the dose eliminated within 24 hours. Fecal excretion also occurred; biliary excretion was minimal. The highest concentration of radioactivity was found in whol e blood, associated with the cellular component. Whole body auto radiography showed a much higher level of radioactivity remaining in males after 24

hours than in females. Four metabolites were identified. One was the primary urinary metabolite and the other identified metabolites were found in the urine. The proposed formation of two metabolites involved the cleavage of the

PO 2 [CH(CH 3 ) 2 ] 2 moiety of bensulide, followed by methylation and oxidation of the sulphur atom. Conjugation with glycine or carboxylation and oxidative desulphuration is proposed to lead to the other two identified metabolites.

870.7600 Dermal penetration-rat NA NA

870.7800 Immunotoxicity - mice 48377701 (2011) 48623701 (2011)
TXR 0055808;

0056257 Unacceptable, guideline
0, 50, 200, or 800 mg/kg/day Increased mortality was observed at 800 mg/kg/day.

Problems with the conduct of the TDAR made confident interpretation of the results impossible.

HASPOC waived this study (van Alstine, 2013, TXR # 0056738)Bensulide Human Health Risk Assessment DP No. D428598

Page 73 of 97 Table A.2.4. Subchronic, Chronic, and Other Toxicity Profile – Bensulide

Guideline No./Study Type MRID No. (year)/

TXR #/ Classification

/Doses Results

Non-Guideline Comparative cholinesterase assay –

rat 49433502 (2014) 49466201 (2014) 49454001 (2014)Acceptable, nonguideline

Animals were treated with a single gavage dose in corn oil at 0, 50, 100, 150, and 200 mg/kg/day in the adult males, 0, 25, 50, 100, and 150 mg/kg/day in adult females, and 0, 20, 40, 60, and 100 mg/kg/day in the pups

Animals were treated once daily for 10 consecutive days at 0, 15, 25, 50, and 75 mg/kg/day in the adults and 0, 5, 10, 20, 40, and 60 mg/kg/day in the pups.

Dams were treated once daily during GD 6-20 (inclusive) at 0, 15, 30, 60, and 90 mg/kg/day In the acute study, the LOAEL in adults was 50 mg/kg/day

based on ChE inhibition in the RBC and brain of females. The NOAEL was 25 mg/kg/day. The LOAEL in the PND 11 pups was 40 mg/kg/day based on ChE inhibition in the RBC

and brain of males and females. The NOAEL was 20 mg/kg/day.

In the repeated dose study, the LOAEL in adults was 25 mg/kg/day based on ChE inhibition in the RBC of females (only sex tested). The NOAEL was 15 mg/kg/day. The LOAEL in the PND 11 pups was 10 mg/kg/day based on ChE

inhibition in the RBC of males. The NOAEL was 5 mg/kg/day.

In the gestational study, the LOAEL in dams and fetuses was 30 mg/kg/day based on ChE inhibition in RBC and brain. The NOAEL was 15 mg/kg/day.

A.3 Executive Summaries

A.3.1 Subchronic Toxicity

870.3100 90-Day Oral Toxicity - Rat

In a subchronic toxicity study ( MRID 43919601 ), male and female Sprague-Dawley rats (10/sex/dose) were given bensulide (92.4% a.i.) in the diet for 13 weeks at doses of 0, 5, 15, 45, or 100 mg/kg/day.

Significantly decreased body weight gains (p <0.01, 19%) were observed for male rats at 100 mg/kg/day. Although not significant, body weight gains for female rats were 12,Bensulide Human Health Risk Assessment DP No. D428598

Page 74 of 97 11, and 14% lower than controls at 15, 45, and 100 mg/kg/day, respectively. Food consumption appeared not affected by treatment. Overall food efficiency was decreased in males at 100 mg/kg/day.

Significantly increased alanine amino-transfer ase levels were observed at 45 mg/kg/day (87% increase in males; 48%, females) and 100 mg/kg/day ( 145%, males and 90%, females). Dose-related inhibition of ChE ac tivity occurred in both sexes. Relative to controls, plasma ChE decreases were 28, 54, and 62% (males) at 15, 45, and 100 mg/kg/day, respectively, and 19, 47, 84, a nd 90% (females) at 5, 15, 45, and 100 mg/kg/day, respectively. Red blood cell ChE decreases were 47 and 59% (males) and 38 and 66% (females) at 45 a nd 100 mg/kg, respectively. Br ain ChE decreases were 18 and 43% (males) at 15 and 100 mg/kg/day, re spectively, and 28 and 58% (females) at 45 and 100 mg/kg, respectively. Increased relative liver weights were observed in males (17%, p<0.01) and females (19% , p<0.001) at 100 mg/kg/day. The hepatic toxicity was corroborated by mild histological changes in th e liver in males (fatty microvesicles at 100 mg/kg/day; vacuolation at 45 and 100 mg/kg/day).

Under the conditions of this study, the NO AEL is 5 mg/kg/day; the LOAEL is 15 mg/kg/day, based on decreased plasma ChE ac tivity in both sexes, decreased brain ChE activity in males, and an equivocal reduction in body weight gain in females.

This subchronic dietary toxicity study in rats is classified as Acceptable/Guideline and satisfies the guideline requirements (§82-1a) fo r a subchronic toxicity study in the rat.

870.3100 90-Day Oral Toxicity - Mouse

Reviewed as the dose-selec tion rational for the chroni c toxicity study (MRID 44161105).

The rational for dose selection was based on results from 0 previously conducted 13- week subchronic study in which 10 CD-1 mice/ sex/dose were dosed with bensulide (92.4 ±0-5%; Lot # CBI 0801) at 0, 30, 100, 300, or 1000 mg/kg/day (MRID 44161104). All animals, including premature decedents were necropsied. After necropsy, the kidneys and lungs of the controls and high-dose animal s and the livers of all the animals were examined histologically. The brain, heart, kidne ys, liver, lungs, ovaries , spleen, and testes were weighed. Mortality, clin ical signs, and water consum ption were not affected by

treatment with bensulide. There were no trea tment related findings in the 30 mg/kg/day animals. The following treatment related fi ndings were observed in the 1000 mg/kg/day animals compared to concurrent controls: decreased mean body weight gain in females ( ↓ 50%; p<0.01) and decreased body weight in males ( ↓ 1 g; p<0.001); decreased overall (weeks 1-13) feed consum ption in both sexes ( ↓ 9-10%); increased liver weight ( ↑ 72- 90%; p<0.001) and increase in liv er lobulation in bot h sexes; liver enlargement in males; increase in the incidence and severity of hepatocyte hypertrophy in both sexes; and a decrease in ovarian ( ↓ 43%; p<0.001) and spleen ( ↓ 26%; p<0.05) weights in females. Findings in the 100 and 300 mg/kg/day dose groups consisted of a reduction in body weight gain in the males ( ↓ 27 and 55%; p<0.001, respectively), an increase in liverBensulide Human Health Risk Assessment DP No. D428598

Page 75 of 97 weights in both sexes ( ↑ 19-42%; p<0.01 and <0.001), and an increase in the incidence and/or the severity of hepatocyte hypertrophy in the anim als of both groups.

870.3150 90-Day Oral Toxicity – Dog

In a 13-week subchronic toxicity study (MRID 44052703), bensulide (92.4% a.i., Lot #CBI 0801) was administered via the diet to four dogs/sex /group at dose levels of 0, 1, 3, 10, or 30 mg/kg/day for 13 weeks.

No treatment-related effects were noted on survival, clinical si gns, body weights, food consumption, ophthalmology findings, clinic al chemistry (including RBC and brain cholinesterase but excluding plasma cho linesterase), urinalysis, and necropsy.

At 30 mg/kg/day, there was sli ght evidence for liver toxicity . Adjusted (for terminal body weight covariate) liver wei ght means were decreased by 19-22% in both sexes. There was

no statistical difference in liver weights at this dose in the chronic toxicity study in dogs. Additionally, periportal lipid depos its were noted in the liver of 7/8 rats, and the eighth rat (a female) had centrilobular lipid deposits . The severity was reported as only very mild or mild. The increase in weight wa s considered slight, and the biological significance of the lipid deposits was unclear , but likely negligible considering the severity. However, liver findings following bensulide treatment have been reported in rats and mice, as well as in the chroni c toxicity study in dogs. Activated partial thromboplastin times were pr olonged in both sexes in the 30 mg/kg/day treatment group at 6 (21-35%) and 13 (33-50%) weeks; this parameter was not evaluated in the chronic toxicity study in dogs. The liver effects and hematological effect were together considered very conservativ ely to be adverse.

The LOAEL was 30 mg/kg/day, based cons ervatively on increased liver weight, increased incidence of liver lipid depo sits, and increased activated partial thromboplastin times. The NOAEL is 10 mg/kg/day.

This study is classified acceptable, guideline and satisfies the guideline requirements (OCSPP 870.3150; OECD 409) for a 90-day oral toxicity study in dogs.

870.3200 21/28-Day Dermal Toxicity – Rat

In a 21-day dermal toxicity study ( MRID 42162002 ), male and female specific pathogen-free Wistar-derived albino rats (Al pk:APfSD strain; 5/sex/dose; 6-8 weeks old) were dermally treated over a 5 cm x 10 cm area of clippe d dorso-lumbar skin with bensulide technical (92.7% a.i.) at dose levels of 0 (sham control), 10, 100, and 1000 mg/kg/day (limit test dose). Dosing occurre d 21 times over a period of 30 days (five days/week). Following each dosing, the appli cation site was covered with an occlusive dressing (gauze patch, a patch of plastic f ilm secured by adhesive bandages, and two pieces of 2.5 cm-wide PVC tape wrapped around the animals) for approximately 6

hours.Bensulide Human Health Risk Assessment DP No. D428598

Page 76 of 97 After each 6-hour exposure period, the dressings were removed and the application sites washed with warm water. On dosing days, animals were fitted with Elizabethan collars to prevent test substance ingestion. Rats were observed for clinical signs and dermal irritation prior to dosing, after each removal of dressings, and at least once daily during non- dosing days. They were weighed dail y, and food consumption was recorded twice weekly. At study termination, cardiac blood sa mples were collected shortly after animal sacrifice for hematological and clinical chemistry determinations. Gross necropsies were conducted, the standard set of organs were fixed for potential histopathology, and the following organs were also weighed: adrenals, brain, kidneys, liver, and testes (males). Only the kidneys of all animals, and the treated and untreated skins and livers of the control (0 mg/kg/day) and hi gh-dose (1000 mg/kg/day) were examined histologically.

There were no deaths, compound-related clin ical signs, or significant changes in body weight or food consumption in any group. A small incidence of dermal trauma was apparently caused by the bandages. No abnormal hematology was seen, and the only clinical chemistry anomaly was a 43% decreas e in plasma triglycerides in the high-dose (1000 mg/kg/day) males compared to controls; females were not affected. In the absence of other findings, th is decrease is of unknown biological significance. There were no dose-related gross lesions or organ weight changes. Some scabbing of treated and untreated skin, due to bandage trauma, wa s observed in all groups. This observation correlates with several histopathologic fi ndings of slight to minimal acanthosis, parakeratosis, and inflammatory infiltration in treated and untreated skin. A number of minimal to slight renal lesions were observe d, but they are not clinically significant and may have represented artifacts. Therefor e, the NOAEL is > 1000 mg/kg/day (limit dose), based on the lack of any observed t oxicity, and the LOAEL was not determined.

Although cholinesterase activity was not determined , this study was classified as Acceptable/Guideline and satisfies the Gu ideline requirement for a 21-day dermal toxicity study (82- 2) in the rat.

In a special 21-day dermal toxicity study ( MRIDs 44801101 and 44809401 ), groups of

Charles River CD rats (10/sex/dose) were dermally applied Bensulide technical (92.1%) at dose levels of 0, 30, 50, and 500 mg/kg for 6 hrs/day for 21 days. The test chemical did not produce treatment-related clinical signs, mortality, or ch anges in body weight and food consumption. Clinical chemistr y and hematology parameters were not measured. Urinalysis, and organ weights were not determined. However, these parameters were not significantly affected in a previous 21-day dermal toxicity study in rats which were dermally treated up to 1000 mg/kg (MRID 42162002; Tox. Doc. No. 009325).

Bensulide at 500 mg/kg produced statistically significant decreases (p<0.01) in plasma cholinesterase (PChE) activity in both ma les and females on days 7, 14, and 22; the decrease (-31% in males & -55% in females) was particularly marked at the end of the study (day 22). In addition, the inhibition of PChE appeared to increase with theBensulide Human Health Risk Assessment DP No. D428598

Page 77 of 97 increased time of treatment. Pl asma cholinesterase inhibitio n was also seen in 50 mg/kg females, but it was not statistically si gnificant. Bensulide at 500 mg/kg also significantly (p<0.05) inhibited brain stem Ch E activity in both males and females, but it had no effect on the ChE activity in cerebe llum and cerebral cortex. In this study, RBC ChE activity was not affected by bensulide.

Therefore, under the conditions of this dermal toxicity study, the LOAEL for ChE inhibition was 500 mg/kg based on significan t inhibition of both brain and PChE activity, and the NOAEL was 50 mg/kg.

The study was classified as Acceptable/non- guideline because this was a special study conducted to obtain information on the potential of bensulide to inhibit ChE activity in plasma, RBC, and brain.

870.3465 90-Day Inhalation – Rat (Not Submitted but Required)

A.3.2 Prenatal Developmental Toxicity

870.3700a Prenatal Developmental Toxicity Study – Rat

In a developmental toxicity study ( MRID 00146585 ), bensulide technical (92.8 % a.i.) was administered to 25 or 26 female Sprague-D awley rats/dose in corn oil by gavage at analytically determined dose levels of 0, 5.5, 23.0 or 95.0 mg/ kg/day from days 6 through 20 of gestation.

Bensulide technical exerted no effects on mate rnal gross pathology, fe rtility, or cesarian parameters. The maternal systemic LOAEL is 95.0 mg/kg/day (HDT), based on tremors, decreased body weight (range: 93-94% of control value) on days 12, 16, and 21 of gestation, decreased body weight gain during days 9-12 (25% control value) and 6-21 (76% of control value) of gestation, decr eased (79% of control value) feed intake during days 13-16 of gestation, and decreased whole and corrected (reproductive tract subtracted) body weights (93% and 91% of co ntrol values, respectively) and increased liver/body weight ratio (112% of control value) at st udy termination. The maternal systemic NOAEL is 23. 0 mg/kg/day (MDT).

The Maternal NOAEL for cholinesterase inhi bition is 5.5 mg/kg/day (LDT), based on a 48% decrease in plasma ChE activity at 23.0 mg/kg/day (LOAEL; MDT) in the absence of any other effects.

The Developmental NOAEL > 95.0 mg/kg/day (HDT), ba sed on the lack of any developmental effects. The devel opmental LOAEL > 95.0 mg/kg/day.

This developmental toxicity study in the ra t is classified Acceptable/Guideline and does satisfy the guideline requirement for a developmental toxi city study (§83-3a)

in the rat.Bensulide Human Health Risk Assessment DP No. D428598

Page 78 of 97 870.3700b Prenatal Developmenta l Toxicity Study - Rabbit

In a developmental toxicity study (MRID 00152845), inseminated New Zealand White rabbits, randomly assigned to one control and three treatment groups of 18 animals each, were administered Betasan ® (bensulide technical; 92.8% a. i.) by oral gavage at doses of 0, 5, 20, or 80 mg/kg/day on gest ation days (GD) 7-19, inclusive.

Cesarean section examinations were performed on all surviving does on GD 29, followed by teratological examination of all fetuses.

No treatment-related effects were observed in the 5 or 20 mg/kg/day groups as compared with controls. Three high-dose animals aborted, one each on GD 18, 27, and 28, and were sacrificed and necropsied. All other an imals survived until scheduled sacrifice. Decreased defecation was observed in 3, 2, 1, and 11 animals and decreased urination was observed in 3, 2, 0, and 11 animals in the control, 5, 20, and 80 mg/kg/day groups, respectively. No other dose- or treatment -related clinical signs of toxicity were observed during the study. Maternal body weight gains were significantly (p ≤ 0.05 or 0.01) less in the high-dose group as compared to the controls throughout the dosing interval with an overall weight loss record ed during the treatmen t interval. Absolute body weights of the high-dose animals were less than the controls beginning on GD 13 but statistical significance (p ≤ 0.01) was reached only on GD 19. After cessation of treatment, does in the high-dose group showed recovery with body weight gains significantly (p ≤ 0.01) greater than the controls. During the dosing interval, food consumption by the high-dose animals was significantly (p ≤ 0.01) less than the control beginning on GD 10. Overall food consump tion was significantly less in the high-dose group for the entire dosing interval (62%; p ≤ 0.01) and the entire gestation period (83%;

p ≤ 0.05) as compared to controls.

Therefore, the maternal toxicity NOAEL is 20 mg/kg/day and the maternal toxicity LOAEL is 80 mg/kg/day based on reduced body weights and weight loss during the

treatment interval.

There were no differences betw een treated and control groups for live fetuses/litter, fetal body weights, or fetal sex ratios. No treatment-related malformations/variations were observed for any external, visceral, or skeletal parameter examined of kits in the treated litters as compared to the c ontrol litters. There was no diff erence in the total number of litters containing fetuses with major malforma tions as compared to controls: 3/15, 1/15, 0/10, and 2/10 affected in the control, 5, 20, and 80 mg/kg/day groups, respectively.

Therefore, the developmen tal toxicity NOAEL is > 80 mg/kg/day and the developmental toxicity LOAEL was not identified.

This developmental toxicity study in rabbits is classified as Acceptable/Guideline and satisfies the guideline requirement (§83-3b) for a developmental toxicity study in

rabbits.Bensulide Human Health Risk Assessment DP No. D428598

Page 79 of 97 A.3.3 Reproductive Toxicity

870.3800 Reproduction and Fertility Effects – Rat

In a two-generation reproduction study (MRID 43948701), Bensulide (92.4% a.i.; Lot No. CDI 0801) was administered to male a nd female Sprague-Dawley CD rats in the diet at concentrations of 0, 25, 150, or 900 ppm for two generations. Premating doses

for the F 0 males were 2.0, 12.3, and 68.2 mg/kg, respec tively, and for the F 0 females were 2.3, 13.2, and 80.8 mg /kg, respectively. Prema ting doses for the F 1 males were 2.3, 14.0, and 86.5 mg/kg, respectively, and for the F 1 females were 2.6, 15.4, and 93.2 mg/kg, respectively. The F 0 generation contained 28 animals/sex/dose and the F 1 generation contained 24 animals/sex/dose. Anim als were given test or control diet for at least 10 weeks then mated within the same dose group.

F 1 animals were weaned on the same diet as their parents. At least 21 litters were produced in each generation. All animals were exposed to test material either in the diet or during lactation until sacrifice.

Although several deaths occurred among treated and control groups of both generations, these were considered incidental to treatment. No overt treatment-related clinical signs of toxicity were observed in the adult animals of either sex or generation. There were no statistically significant differences between treated and control groups of either sex or generation for absolute body weights, body weight gains, food consumption, or gross or histopathological findings.

Therefore, the NOAEL for systemic effects > 900 ppm (82.8 mg/kg/ day; HDT) and the

LOAEL was not determined.

Terminal cholinesterase activity was measured in plasma, red blood cell, and brains of
the adult animals of both generations. Baseline or pretreatment activities were not
measured. In F 0 males, plasma cholinesterase activity was significantly (p ≤ 0.01) reduced in the mid- and high- dose groups as compared to controls with percent inhibition (%I) 21 and 54%, respectively. High-dose F 0 males also had significantly (p ≤ 0.01) reduced RBC activity (%I = 32). Mid- and high-dose F 0 females had significantly (p ≤ 0.01) reduced plasma activity (%I = 43 and 76, respectively) while high-dose F 0 females also had significantly (p ≤ 0.01) reduced RBC (%I = 57) and brain (%I = 68) activities. Plasma activity was significantly (p ≤ 0.01) reduced in all treated F 1 male groups as compared to controls (%I = 28, 30, and 62, respectiv ely). Mid- (p ≤ 0.05) and high-dose (p ≤ 0.01) F 1 males also had significantly reduced RBC activity (%I = 11 and 42, respectively). Mid- and high-dose F 1 females had significantly (p ≤ 0.01) reduced plasma activity (%I = 47 and 80, respectively) while high-dose F 1 females also had significantly (p ≤ 0.01) reduced RBC and brain activ ities (%I = 63 and 51). The 51-68% inhibition of brain ChE activity in females in the high-dose (900 ppm) group indicates that dosing was conducted at an adequately high level; higher doses would likely yield an unacceptable level of mortality.Bensulide Human Health Risk Assessment DP No. D428598

Page 80 of 97 Therefore, the LOAEL for cholinesterase inhibition is 25 ppm ( 2.3 mg/kg/day; LDT) based on inhibition of plasma enzyme activity in F 1 males. The cholinesterase

inhibition NOAEL was not identified.

No statistically significant differences occurred for absolute body weights, body weight gains, or food consumption of the F 0 or F 1 females during gestation or lactation for any treated group as compared to controls. High-dose F 0 males and females had low fertility indices with only 21 of 28 males siring litters and only 24 of 28 females becoming pregnant. However, this effect was not repeated in the F 1 generation. There were no statistically significant differences between treated and control groups for number of litters or pups/litter during lactation of either generation. Survival and viability of the F 1 pups was similar between treated and control groups. However, survival was greatly reduced in the high-dose F 2 pups with overall (day 0-21) survival only 61%. This was due mainly to a low viability index of 74% for lactation days 0-4.

Therefore, the LOAEL for reproductive t oxicity is 900 ppm (93.2 mg/kg/day; HDT)

based on reduced F 2 pup survival. The corresponding NO AEL for reproductive toxicity is 150 ppm (15.4 mg /kg/day; MDT).

This study is classified as Acceptable/ Guideline and does satisfy the guideline requirement for a reproducti on study (§83-4) in rats.

A.3.4 Chronic Toxicity

870.4100a (870.4300) Chronic Toxicity – Rat

870.4100b Chronic Toxicity – Dog

In a chronic toxicity study (MRID 44066401), bensulide (92.4% a.i.) was administered to four dogs/sex/dose by feeding at dose levels of 0, 0.5, 4, or 30 mg/kg/day for 52

weeks.

No treatment-related effects were noted on survival, clinical si gns, body weights, food consumption, ophthalmology findings, urinalysis, and necropsy.

In the 30 mg/kg/day treatment group, there was inhibition (p ≤ 0.05) of RBC cholinesterase in females at Weeks 26 and 39 ( ↓ 32-39%) and in males at Week 52 ( ↓ 45%); however, decreases (not statistically significant) were noted in both sexes at all time points at this

dose. No effect was clearl y present on brain (pons and cer ebellum) cholinesterase.

At 30 mg/kg/day, mild effects were also noted in the liver (primarily the female). An increased incidence of moderate focal pigm ented Kupffer-cell accumulation (positive, for the presence of hemosiderin [Prussian Blue stain], neutral fat and diastase resistance [Periodic Acid Schiff stain]) was noted in 2/ 4 females compared to 0/4 controls (notBensulide Human Health Risk Assessment DP No. D428598

Page 81 of 97 observed in any male). Focal liver inflammati on occurred at a similar incidence in the treated dogs compared to controls (n=4, 3 tr eated males vs 3 controls; 4 treated females vs 3 controls); however, severity was increa sed (2 mild treated males vs 0 controls; 3

mild to moderate treated females vs 0 cont rols). The stain for fat was positive with a slightly increased incidence and severity in females (2/4 very mild to mild treated vs 1 very mild control). Liver weights were increas ed, but were not statis tically different than the controls. Additionally, ad justed (terminal body weight covariate) adrenal gland weights were increased by 30% in males; however, there was no corroborating evidence

of an adverse effect on the adrenals.

The LOAEL for this study is 30 mg/kg/day based on the RBC cholinesterase

inhibition and mild indica tions of hepatotoxicity (Kupffer-cell accumulation, inflammation, and fatty). The NOAEL is 4 mg/kg/day.

This study is classified acceptable, guideline and satisfies the guideline requirement (OCSPP 870.4100b; OECD 452) for a ch ronic toxicity study in dogs.

870.4100b Chronic Toxicity – Dog

In a chronic toxicity study (MRID 41112301), bensulide (93.8% a.i.) was administered in the diet to five dogs/sex/dose at dose levels of 0, 2, 10, or 50 mg/kg/day for 52

weeks.

No treatment-related effects were note d on ophthalmology findings, urinalysis, and organ weights. No adverse effects were noted at 2 or 10 mg/kg/day.

At 50 mg/kg/day, excessive mortality was not ed. In this group 9/10 dogs died or were terminated moribund. Mortality or morbidity ty pically was preceded by a drastic decrease in food consumption for 1-4 weeks prior to deat h. Clinical signs included those indicative of cholinesterase inhibition, as well as gene ral malaise: loss of appetite, drastic weight loss, excessive salivation, tarry stools, red (blood y) stools, diarrhea, hypothermia, pale gum and mucous membranes, lethargy, and emaciation. Several dogs exhibited diarrhea, emesis, and/or excessive salivation beginni ng during the first week of the study. The single surviving female in this group exhibi ted occasional diarrhea, tarry stools, emesis, and excessive salivation. Body weight decreases in the ma les was progressive beginning

after 3-11 weeks of treatment with morta lity occurring after 8-21 weeks. Body weight

decreases in the females that died or were terminated early was progressive beginning after 7-17 weeks of treatment with mortality occurring after 13-20 weeks. Anemia (as evidenced by decreased erythrocytes, hema tocrit, and hemoglobin) was noted in the males and one female. Serum glutamic-pyruv ic transaminase and alkaline phosphatase may be increased, but results were highly vari able. Livers were pale and/or discolored. The following findings were noted during micr oscopic pathology: fibrosis and chronic inflammation of the thymus, erythroid/my eloid bone marrow depletion, inflammation and/or degeneration of the sk eletal muscle, and liver ch anges (hepatocyte hypertrophy, biliary proliferation/hyperplasi a, inflammation, and the presen ce of small vacuoles in the hepatocytes).Bensulide Human Health Risk Assessment DP No. D428598

Page 82 of 97 Acetylcholinesterase was decreased in the pons but not in the cerebellum nor in the erythrocytes. Inhibition (p ≤ 0.05) in the pons was 20% and 24% in males and 18% and 19% in females at 2 and 10 mg/kg/day, respec tfully. As a decrease was only noted in the pons (and not in the RBCs which is most sensitive in other studies) and the dosedependency was questionable, the effect on the pons was considered an equivocal finding

The LOAEL for this study is 50 mg/kg/day based on increased mortality, clinical signs of toxicity, decreased body weight a nd food consumption, discolored liver, and several microscopic lesions (fibrosis a nd chronic inflammation of the thymus, erythroid/myeloid bone marrow depletion, inflammation and/or degeneration of the skeletal muscle, and liver change s). The NOAEL is 10 mg/kg/day.

This study is classified acceptable, non-guideline . Excessive mortality was noted at the high dose, which means it does not sa tisfy the guideline requirement (OCSPP 870.4100b; OECD 452) for a chronic toxicity study in dogs. However, the study was otherwise conducted in a valid manner and provides meaningful results. A.3.5 Carcinogenicity

870.4200a Carcinogenicity Study – Rat (see 870.4300)

870.4200b Carcinogenicity (feeding) - Mouse

In a mouse oncogenicity study ( MRID 44161105 ), bensulide (92.4 ±0.5% a.i., Lot # CBI 0801) was administered for 78 weeks in the diet to 50 CD -1 mice/sex/dose at levels to achieve constant weekly doses of 0, 1, 50, or 200 mg/kg/day. An additional 10 mice/sex/dose were used to provide samples for plasma and red blood cell cholinesterase assessments at 13 weeks, and further cholinesterase assessments, including brain cholinesterase at 52 weeks; th ese animals were terminated and discarded at 52 weeks. All remaining animals we re sacrificed at 78 weeks of the study.

Survival rates, clinical observations, and hematological parameters were unaffected by

treatment with bensulide. Chronic toxic ity was characterized by reduced (p<0.01 or <0.001) cholinesterase levels (plasma, ↓ 92-96%; erythrocyte, ↓ 40-51%) in the high-dose males and females and reduced brain cholinesterase in the high-dose females ( ↓ 14%). Additionally in the high-dose males, decreased overall body weight gains ( ↓ 32%; p<0.001), increased absolute a nd relative liver weights ( ↑ 38-43%; p<0.001), and histopathological changes of the liver (pale fo ci, cell atypia, and cell foci) were observed. In the 50 mg/kg/day animals, reduced (p<0.01, or 0.001) plasma ( ↓ 88-92%) and RBC ( ↓ 31-37%) cholinesterase activities were observed and brain cholinesterase activity was reduced ( ↓ 12%; p<0.05) in the fema les. Additionally, overall body weight gain in the mid-dose males was reduced by 16% (p<0.05) compared to controls.

The chronic LOAEL is 50 mg/kg/day based on inhibition of plasma and erythrocyte cholinesterase activity in the 50 and 200 mg /kg/day group animals, inhibition of brain cholinesterase activity in the mid- and high- dose females, decreased body weight gain in the mid- and high-dose males, and increas ed liver weights, and histopathologicalBensulide Human Health Risk Assessment DP No. D428598

Page 83 of 97 changes in the high-dose males. Th e chronic NOAEL is 1 mg/kg/day.

Under the conditions of this study, there was no evidence of carcinogenic potential.

Dosing was considered adequate based on decreased plasma, RBC, and brain cholinesterase activities, decreased body weight gains, and by increased liver weights and histopathological changes of the liver.

This study is classified as Acceptable/Guid eline and satisfies the guideline requirements for a carcinogenicity st udy (§83-2b) in mice.

870.4300 Combined toxicity/car cinogenicity – rat

In a combined chronic/oncogenicity study ( MRIDs 43919602 and 44161101 ), bensulide (92.4 ±0.5% a.i., Lot # CBI 0801) was administered in th e diet for 104 weeks to 80 Sprague-Dawley rats/sex/group at levels to ach ieve constant weekly doses of 0, 1, 15, or 60 mg/kg/day. At approximately the 26, 52, a nd 78 week intervals, 10 rats/sex/group were terminated, and all remaining animals were sacrificed at 104 weeks of the study.

Survival rates, ophthalmoscopic findings , clinical observations, hematological parameters, urinalysis findings, and gross findings were unaffected by treatment with bensulide. Chronic toxicity in rats recei ving 60 mg/kg/day was ch aracterized in both

sexes by reduced (p < 0.05, <0.01 or <0.001) cholinesterase levels (plasma, ↓ 59-93%; erythrocyte, ↓ 44-80%; and brain, ↓ 20-39%) and, in the males, by increased absolute liver weights ( ↑ 4-22%) and mild histopathological changes of the liver (hepatocyte vacuolation and eosinophilic foci). In the 15 mg/kg/day animals, reduced (p<0.05, <0.01, or 0.001) plasma ( ↓ 36-73%) and erythrocyte ( ↓ 20-40%) cholinesterase activities

were also observed.

The chronic LOAEL is 15 mg/kg/day based on inhibition of plasma and erythrocyte cholinesterase activity in the mid- and high-dose group animals, inhibition of brain cholinesterase activity in the high-dose anim als, and increased liver weights and mild histopathological changes in the high-dose ma les. The chronic NOAEL is 1 mg/kg/day.

Under the conditions of this study, there was no evidence of carcinogenic potential.

Dosing was considered adequate by decreased cholinesterase activity (plasma, red blood cell, and brain) in high-dose animals and by increased absolute liver weights and liver histopathological changes in the high-dose males.

This study is classified as Acceptable/Guid eline and satisfies the guideline requirements for a chronic toxicity study (§83-1) and a carcinogenicity study (§83-2) in the rat.

A.3.6 Mutagenicity

The available studies clearly indicate that bensulide is not genotoxic. Additionally, theBensulide Human Health Risk Assessment DP No. D428598

Page 84 of 97 negative mutagenicity studies support the lack of an oncogenic effect in the rat and mouse long-term feeding studies and also the absence of significant reproductive or developmental toxicity attribut able to a mutagenic mode of action (i.e., decreased total implants, increased resorptions). Based on th e overall results, there is no concern for mutagenicity.

The submitted test battery sa tisfies the new mutagenicity initial testing battery guidelines; therefore, no Categor y III study or additional furt her testing is required at

this time.

In a reverse gene mutation assay in bacteria ( MRID 00153493 ), strains TA98, TA100, TA1535, and TA1537 of S. typhimurium were exposed to bensulide technical (92.9% a.i.) at concentrations of 0 (dimethyl sulfoxide solv ent control; DMSO), 0.005, 0.014, 0.041, 0.123, 0.370, 1.111, 3.333, 10.000, 25.000, or 50.000 μL/plate (TA100) or 0
(DMSO), 0.037, 0.111, 0.333, 1.000, or 3.000 μ L/plate (TA98, TA1535, and TA1537) in the presence and absence of mammalian metabolic activation (metabolic activation mixture containing the S9 fraction from liv ers of Aroclor 1254-induced Sprague-Dawley rats).

Bensulide technical was tested up to and a bove levels at which it precipitated onto the culture medium ( ≥ 0.041 μL/plate for TA100; ≥ 1.000 μL/plate for TA98, TA1535, and TA1537). The positive controls did induce the appropriate responses in the corresponding strains. There was no evid ence of induced mutant colonies over background.

This study is classified as Acceptable/Guideline. It does satisfy the requirement for

Guideline 84-2 for in vitro mutagenicity (bacterial reverse gene mutation) data.

In a mammalian cell gene mu tation assay (TK locus; MRID 43273901 ), mouse lymphoma L5178Y cultured cells cultured in vitro were exposed to bensulide technical (92.4 ± 0.5% a.i.; given in MRID 43919602) in dimethyl sulfoxide (DMSO) at concentrations of 8, 14, 16, 21, 24, 28, 32, 35, 40, or 42 μg/mL in the absence and at 16,

24, 28, 32, 35, 40, 42, 48, 49, or 56 μ g/mL in the presence of mammalian metabolic activation (S9 fraction containing homogenate from Aroclor 1254-induced rat liver).

Bensulide technical was tested up to cyto toxic concentrations, based on preliminary cytotoxicity assays demonstrating signif icant cytotoxicity at doses near 30 μg/mL and total cell death at doses as low as 25-30 μg/mL. There was no evidence of

induced forward mutation at the TK locus over solvent control values at any dose tested.

This study is classified as Acceptable/Guideline. It does satisfy the requirement for

Guideline 84-2 for in vitro mutagenicity (gene mutation in mammalian cells) data.

In a C57BL/6JfCD-1/Alpk mouse bon e marrow micronucleus assay ( MRID 41902602 ), 5 animals/sex/dose were treated with a single oral (gavage) dose of bensulide technical (92.7% a.i.) in corn oil (vehicle) at dose s of 250 or 400 mg/kg (constant dose volume ofBensulide Human Health Risk Assessment DP No. D428598

Page 85 of 97 10 mL/kg). Bone marrow cells were harvested at 24, 48 and 78 hours post- treatment.

There were no signs of toxicity during the study. Bensulide technical was tested at an adequate dose, since the 400 mg/kg dose level (HDT) was selected based on the results of a preliminary acute toxicity study (2 anim als/sex/dose) in which mortalities were

observed at doses of 500 mg/kg or greater, but not at 400 mg/kg or less. The positive control (cyclophosphamide) induced the appropriate response. There was no significant increase in the frequency of micronucleated polychromatic erythrocytes in bone marrow after any treatment time.

This study is classified as Acceptable/Guideline. It does satisfy the requirement for

Guideline 84-2 for in vivo mutagenicity (mouse bone marrow micronucleus) data.

A.3.7 Neurotoxicity

870.6100 Delayed Neurotoxicity Study – Hen

In an acute delayed neurotoxicity study ( MRID 43334302 ), Bensulide (tech., 92.4% a.i.) was assessed using groups of 15 single comb white leghorn laying hens ( Gallus gallus domesticus ) given a single neat gavage dos e of Bensulide (2000 mg a.i./kg nominal dose; actual dose was 2262 mg/kg in a dosing volume of 2 mL/kg). An acute oral toxicity study (43306301) determined an LD 50 of 3221 mg/kg for Bensulide in the domestic laying hen. Positive controls (12 birds) were given 800 mg TOCP/kg and 12 birds given corn oil served as vehicle controls. Three birds of each group were

sacrificed at

- 48 hrs for activity analysis of neurotoxic esterase (NTE) in brain and spinal cord and acetylcholinesterase (AChE) in brain. Behavior assessments (locomotor ability) were conducted on nine birds from both control groups and 12 birds from the Bensulide group over a period of 21 days. Pathology (brain, spinal column and peripheral nerves) was evaluated in all remaining animals at Day 21.

Based on the study results, Bensulide did not induce acute delayed neurotoxicity in the domestic laying hen at the dose tested. NTE activity was not affected by treatment. A non-significant decrease of

- 24% was observed for brain cholinesterase in treated hens.

This study meets the requirement s of § 81-7 and is classified as Acceptable/Guideline because, although animals were not tested at the LD 50 and no signs of neurotoxicity were
observed, animals were tested at the limit dose of 2 g/kg.

870.6200 Acute Neurotoxicity Screening Battery

In an acute neurotoxicity screening st udy (MRID 43195901), 22 CD rats/sex/group were administered single gavage doses of 0, 30, 100 or 300 mg bensulide (tech., 92.4% a.i.)/kg (males) or 0, 15, 50 or 150 mg/kg (females) in 5 mL/kg corn oil. Functional observational battery (FOB) and motor activity tests were conducted on 12 rats/sex/dose pretreatment, on the day of dos ing (day 0) and days 7 and 14 post-dosing. Plasma, erythrocyte and brain cholinestera se (ChE) activities were measured from 5Bensulide Human Health Risk Assessment DP No. D428598

Page 86 of 97 rats/sex at pretreatment, da y 0 (6.25 and 6.75 hrs post- dosing) and day 15. Six perfused control and high dose rats/sex were evaluated for neuropathology.

At 150 mg/kg (females only), an increased incidence of diarrhea, flaccid abdominal and/or body tone (all 6/12 vs. 1, 2 and 2, controls) and pi npoint pupils (3/12 vs 0, controls) were observed on Day 0 in the FO B. At 300 mg/kg (males only), one death occurred on Day 1, preceded by clinical signs (salivation, lacrimation/ocular discharge, decreased respiration, hypothermia, and fur st aining on muzzle and ventral surface). A second male exhibited abnormal respirati on, tremors, hypoactivit y, dehydration and fur staining between Days 1-3. In the FOB, incr eased incidence of decreased arousal and locomotor activity (for both, 7/12 vs. 3, controls) were observed. A slight but statistically significant depression of body we ight (-6.6%) was also observed on Day 7.

No treatment-related effects on motor activity or macroscopic/microscopic neuropathology were reported. The LOAEL is 150 mg/kg, based on minimal, transient clinical signs consistent with cholinestera se inhibition in females. The NOAEL is 100 mg/kg.

At 50 mg/kg (females only), plasma Ch E was decreased on day 0 by 80% less than controls (not significant). At 100 mg/kg (m ales only), plasma ChE was decreased on day 0 by 53% (not significant). At 150 mg/kg (females onl y) on day 0, reductions were observed in plasma ChE (89% less than c ontrols, p<0.01) and erythrocyte ChE (37% less than control, p<0.01) both of which show ed partial recovery by day 15. However, a significant decrease (73% of control, p<0.01) in brain ChE for high-dose females was noted on day 15 which was not present at day 0 (18% less than contro ls, not significant). At 300 mg/kg (males only), statistically si gnificant ChE inhibition was observed only in the high-dose groups. On day 0, there were si gnificant decreases in brain ChE (62% of control, p<0.01), plasma ChE (19% of control, p<0.01), a nd erythrocyte ChE (60% of control, p<0.01) for males of the high dose (300 mg/kg) gr oup. At day 15, brain ChE was still significantly reduced (73% of control, p<0.01) but values for plasma and erythrocyte ChE had returned to normal.

The plasma ChE inhibition LOAEL is 50 mg/kg, based on 80% inhibition (no p) of plasma cholinesterase activity in fema les on Day 0. The plasma ChE NOAEL is 15 mg/kg.

The RBC ChE inhibition LOAEL is 150 mg/kg, based on 37% inhibition (p ≤ 0.01) of RBC ChE activity in females on Day 0. The RBC ChE NOAEL is 50 mg/kg.

The brain ChE inhibition LOAE L is 150 mg/kg, based on 18% i nhibition (no p) of brain ChE activity in females on Day 0 and 27% inhibition (p ≤ 0.01) on Day 15. The brain ChE NOAEL is 50 mg/kg.

This study is classified as Acceptable/Guid eline and satisfies the guideline requirement for an acute neurotoxicity study in rats (§81-8ss).Bensulide Human Health Risk Assessment DP No. D428598

Page 87 of 97 870.6200 Subchronic Neurotoxicity Screen ing Battery (Not Submitted; Not Required – Waived; Leshin, 2015, TXR # 0057280)

870.6300 Developmental Neurotoxicity Study (Not Submitted; Not Required – Waived; Leshin, 2015, TXR # 0057280)

A.3.8 Metabolism

870.7485 Metabolism – Rat

In a metabolism study ( MRIDs 42007901-42007904 ), bensulide technical, labelled with

14 C in the phenyl ring (> 96.4% radiopurity; 925 MBq/mMole) was dissolved in corn oil (vehicle) and administered to Sprague-Dawley rats (5/sex/group; 7-8 weeks of age; 185- 235 g body weight) following three treatment regimes. Animals in Group I received a single oral dose of radioactive bensulide at 1 mg/kg of body weight. Animals in Group II received 14 consecutive doses (1 mg/kg/da y) of non-radioactive bensulide technical (99% a.i.) in corn oil, followed by a 1 mg/ kg dose of radiolabelled bensulide technical in corn oil on day 15. Group III anim als received a single oral dose of radiolabelled bensulide technical at 100 mg/kg of body weight. An additional group of animals (Group IV; 3/sex/group) were given a single oral dose of radiolabelled bensulide technical at 1 mg/kg of body weight and were subsequently used for autoradiological

radiolabelled carbon dioxide release determ inations. Administration by gavage was used for all treatment groups, and the volume of the corn oil and bensulide technical solution was kept at a consta nt of 4mL/kg of body weight.

For animals in Groups I-III, urine and feces were collect ed at 12, 24, 36, and 48 hours post-dosing and at 24- hour intervals ther eafter until 7 days after dosing with

radioactive bensulide. All animals in Groups I-III were sacrificed 7 days after

treatment with radioactive bensulide techni cal, and the following organs were removed and assayed for radioactivity: blood, liver, kidneys, muscle, fat lungs, uterus, heart, bone, spleen, thyroid, salivary glands, brain, adrenals, ovaries, testes, pancreas, gastrointestinal tract (stomach, small and la rge intestines, and caecum) and its contents, and the residual carcass. Radioactivity was determined by tissue combustion and/or liquid scintillation counting. For Groups IV an imals, two rats of each sex were used for the autoradiography study and 1 rat of each sex was used or the carbon dioxide study.

In the autoradiography study, animals were s acrificed with Halothane at 24 hours after dosing with radioactive bensulide technical. The animals were then immediately frozen

in a mixture of hexane and solid carbon dioxi de. Each frozen carcass was embedded in a block of 2% carboxymethyl cellulose, and longitudinal sagittal section of about 20 μM thickness were cut and representative sections freeze-dried and subjected to autoradiography. In the carbon dioxide study, 14 C-radiolabelled derived from the

metabolism of radioactive bensulide technical and present in expired air was collected by passing the air through a 2N NaOH solution at 6, 12, 24, 36, and 48 hours after dosing.Bensulide Human Health Risk Assessment DP No. D428598

Page 88 of 97 The major route of excretion was via the urine, with peak urinary excretion of 14 Cbensulide equivalents occurring between 0 to 24 hours for males and females in the lowdose group (Group I; 1 mg/kg) and in the high-dose group (Group III; 100 mg/kg). In Group I, total urin ary excretion of 7 days after administration of radioactive bensulide technical accounted for 70 and 75 percent of the administered dose in males and females, respectively. Of these totals, 57 and 72 percent were excreted during the first 24 hours after dosing for males and females, respectively. In Gr oup III, total urinary excretion accounted for 75 and 87 percent of the administered dose in males and females, respectively. Of these totals, 64 and 76 percent were excreted during the first 24 hours after dosing for males and females, respectively.

For Group II (prior 14-day ad ministration of non-radioactive bensulide technical before radioactive bensulide administration, both at 1 mg/kg), total urinary excretion of radioactivity over 7 days past dosing with radioactive bensulide accounted for 79 and 88 percent of the administered dose in males and females, respectively. Of these totals, 63 and 83 percent were excreted during the first 24 hours after dosing for males and females, respectively. For Gr oup IV, urinary excretion of 14 -C radioactivity derived from bensulide technical over a 48-hour period accounted for 67% for one male and 86% in

one male.

For Group I, total fecal excretion of radioactivity derived from 14 C-bensulide technical over 7 days post-dosing accounted for 22 and 20 percent of the administered dose in males and females, respectively. Of these totals, 18 percent was excreted during the first

24 hours for both males and fema les. For Group III, total feca l elimination over 7 days post-dosing of bensulide-derived radioactivity accounted for 22 and 11 percent of the administered dose for males and females, resp ectively. Of these totals, 20 and 8 percent were excreted during the first 24 hours after dosing for males and females, respectively. In Group II animals, total fecal excretion of radioactivity over 7 days post-dosing accounted for 14 and 8 percent of the admi nistered dose for males and females, respectively. Of these totals, 9 and 6 percent were excreted during the first 24 hours post-dosing for males and females, resp ectively. In Group IV, fecal excretion of radioactivity over 48 hours pos t-dosing accounted for 12% of the administered dose in

one male and 7% in one female.

The amount of residual radioactivity in all organs/tissues except for the liver (0.02 to 0.21% of the dose) from all rats was low at 7 days after single oral administration of

radioactive bensulide technical. The radio activity found in the carcasses and in other

tissues accounted for 0.3% to 2.5% and less than 0.1% of the administered dose, respectively. The highest concentration of radioactivity was f ound in whole blood. The majority of the radioactivity in the blood was associ ated with the cellular component. In general, less well perfused ti ssues showed lower concentra tions of radioactivity. Whole body autoradiography of rats killed 24 hours afte r dosing showed that, in male rats, the majority of the radioactivity was presen t in the blood, lung, spleen, bone marrow, and the glandular part of the stomach, the contents of the intestines, and in the intestinal walls. Moderate amounts of radioactivity was found in the liver, kidney, salivary glands,Bensulide Human Health Risk Assessment DP No. D428598

Page 89 of 97 the capsule of the seminal vesicles, nasal passages and the white matter of the brain. The intensity of radioactivity in the female rats was much lower than in the male rats.

In a biotransformation study (MRID 42225401), bensulide metabolites were quantitated

and identified in rat urine and fecal extracts from previous studies (MRID 42007901- 42007903). To obtain sufficient material to confirm metabolite identities, four successive daily doses of 50 mg [ 14 C]-bensulide/kg were administered to 5 SpragueDawley female rats (bulk collection experiment; 99% a.i., unlabeled, Batch No. Y06379/006; >98.0% a.i., [ 14 C]-labeled, Batch No. Y06379/00 5). Biliary excretion was

assessed in one male and one female rat with cannulated bile ducts given an oral dose of 100 mg [ 14 C]-bensulide/kg.

No animals died before scheduled sacrifice in either experiment. In the bulk collection experiment, 52.5% of the administered dose was recovered in the urine and 16.3% in the feces. In cannulated rats, a substantially hi gher fraction of the given dose was in the feces (40.9% in the male, 68.6% in the fema le), possibly due to poor intestinal wall absorption. Biliary excretion was minimal (5 -6% of dose) and biliary metabolites were not analyzed; the mass balance accounting was acceptable (109.2%-114.4%).

Bensulide metabolites found by TLC in excret a from previous studies accounted for

about 59-78% of the administered dose in the urine and about 2.5-8.3% in the feces, distribution varying with sex and dose. Four metabolites were identified. Metabolite I

was the most abundant in the urine for all doses in both sexes (26-58% of given dose) whereas in fecal extracts, Metabolites I, II, or IV predominated (each 0.25-3.4% of dose). Unidentified metabolites individually represented < 3% of the dose except urinary metabolite “H” ( ≤ 16.1% of dose) and one fecal metabolite (TLC spot 6; ≤ 6.23% of dose). Metabolite I and II formation is proposed to involve cleavage of the

PO 2 [CH(CH 3 ) 2 ] 2 moiety of bensulide, followed by methylation and oxidation of the sulphur atom. Conjugation with glycine or carboxylation and oxidative desulphuration is proposed to lead to Metabolite III and IV formation, respectively.

This study is classified acceptable/guideline. It was intended to satisfy the guideline requirement for a metabolism st udy (§85-1) in rats together with four previous studies (MRIDs 42007901-42007904). Together thes e metabolism studies satisfy the Guideline (§85-1) requirements for metabolis m data for bensulide technical in rats.

870.7600 Dermal Absorption – Rat (Not Submitted; Not Required)Bensulide Human Health Risk Assessment DP No. D428598

Page 90 of 97 A.3.9 Immunotoxicity

870.7800 Immunotoxicity

In an immunotoxicity study (MRID 48377701) , bensulide (94.12% a.i., Lot No. TQBTS1001-019) in 1% methyl cellulose in wate r was administered via gavage to female B6C3F1 mice (8/group) at dose levels of 0, 50, 200, or 800 mg/kg/day for 28 days. The

female mouse was selected as the defa ult species/sex for immunotoxicity study. Cyclophosphamide (positive control) was injected intraperitoneally at a dose of 80 mg/kg approximately 24 hours prior to sacrifice. On study day 25, each mouse was immunized with sheep red blood cell (SRBC) via an intraperitoneal injection (2x10 8 SRBC/animal). On Day 29, T-cell dependent antibody respons e (TDAR) was determined with an antiSRBC plaque forming cell (PFC) assay.

Two animals in the 800 mg/kg/day group died. These animals demonstrated labored breathing, hypoactivity and were cold to th e touch. The gross necropsy indicated that

these deaths were due to toxic response to bensulide. There was an overall weight gain in all dose groups and the vehi cle control group. The body weight changes did not indicate any remarkable departures from normal animal growth or feeding behavior. The mean absolute and relative spleen and thymus wei ghts of animals in the test groups did not show significant differences from controls.

The results of the TDAR were considered unacceptable. The performing laboratory did not follow the original study protocol. The amended procedure stated that additional rabbit anti-mouse IgG was added to one of the duplicate tubes containing the splenocytes, sheep red blood cells and guinea pig complement to allow the detection of IgG secreting PFCs in addition to the IgM secr eting PFCs. The total PFCs per 10 6 cells was then calculated by combining PFC of two tubes to gether. The principle of the anti-SRBC PFC assay is to measure the effect of test subs tance on the anti-SRBC IgM secreting cells. The addition of IgM PFCs and IgG PFCs from both tubes as the total plaques formation was misleading and flawed. Nonetheless, the proc edures for measuring IgG secreting cells and interpretation of data in this study were incorrect. De tailed comments are described

in the reviewer’s comment section of this DER.

In addition, the responsiveness of the immunization in this study was questionable. The study report claimed the response of the vehi cle control animals exceeded the minimum expectations (800 total plaques/1x10 6 spleen cells) by combining both tubes including the IgM PFCs and the IgG PFCs. This statement was incorrect because the stated IgG PFC tube would already have in cluded IgM and IgG PFCs; it would be double counting if combining both tubes. The purpose of the duplicate tubes was to obtain an average of the PFCs formation for each spleen. The individu al animal data in this study on the IgM plaques formation indicated that the animal s had not been properly stimulated after SRBC injection (e.g., only one animal in the vehicle control group responded with greater than 800 PFCs per 10 6 cells). The results suggested that antigen (SRBC) might have been accidentally injected into the intestinal tract.Bensulide Human Health Risk Assessment DP No. D428598

Page 91 of 97 The report of the study suggests that the performing laborator y lacks understanding of the immunotoxicity study. The performing laboratory needs to establish a standard operation procedure (i.e., test procedures, SRBC antigen injection technique by i.v. or i.p., and establish optimum amount of complement to be added to the assay tube) and validate its proficiency.

This immunotoxicity study in mice is Unacceptable/guideline and does not satisfy the guideline requirement for an immunotoxicity study (OPPTS 870.7800)

. This data requirement was waived by HASPOC (van Alstine, 2013, TXR # 0056738).

A.3.10 Special/Other Studies

Non-guideline Comparative Cholinesterase Assay – Rat

The purpose of this non-guideline study was to identify any sensitiv e populations that may exist (pregnant females, immature (PND 11) rats, or fetuses) to the cholinesterase (ChE) inhibitory effects of bensulide, an organophosphate. Toxicity was evaluated in each of these lifestages/sub-populations and comp ared to adults. Both acute and repeated dose regimens were evaluated, as well as treatment during the organogenesis and fetal phases of pregnancy (gestation day [GD] 6-20).

In the acute study (MRID 49433502), young adult Sprague-Dawley rats and PND 11 pups (10/sex/dose) were treated by a single gavage (5 mL/kg) dose with bensulide in corn oil. The dose groups were 0, 50, 100, 150, a nd 200 mg/kg/day in the adult males, 0, 25, 50, 100, and 150 mg/kg/day in adult females, and 0, 20, 40, 60, and 100 mg/kg/day in the

pups.

In the repeated dose study (MRID 49466201) , young adult Sprague-Dawley rats and PND 11 pups (10 adult females/dose [no male adults] and 10 pups/sex/dose) were treated by gavage (5 mL/kg) with bensulide in corn oil. The dose groups were 0, 15, 25, 50, and 75 mg/kg/day in the adults and 0, 5, 10, 20, 40, and 60 mg/kg/day in the pups. Animals were treated once daily for 10 consecutive days.

In the gestational study (MRID 49454001), adult Sprague Dawley rats were bred and pregnant females (10/dose) were treated by gavage (5 mL/kg) with bensulide in corn oil once daily during GD 6-20 (inclusive). The dose groups were 0, 15, 30, 60, and 90 mg/kg/day.

In all studies, blood and brain samples were collected at the ti me of peak effect, previously determined to be 16 hours after tr eatment of adults and pups. Samples were processed and assayed for cholinesterase levels by the modified Ellman’s method. Additionally, mortality and c linical signs were evaluate d in the acute study. Body weights were also evaluated in the repeated and gestational studies. A necropsy was also performed on all animals in the gestational study only.Bensulide Human Health Risk Assessment DP No. D428598

Page 92 of 97 In all studies, no adverse treatment-related eff ects were noted on mortality, clinical signs, body weight, body weight gains, or gr oss pathology (gestational study).

Dose-dependent decreases in cholinesterase activity were observed in the brain and RBC

in all three studies.

In the acute study, decreases (p ≤ 0.01) in cholinesterase activity were noted as follows: (i) adult male RBC at 100 mg/kg/day and above ( ↓ 22-69%); (ii) adult female RBC at 50 mg/kg/day and above ( ↓ 26-89%); (iii) adult male brain at 100 mg/kg/day and above ( ↓ 14- 46%); (iv) adult female brai n at 50 mg/kg/day and above ( ↓ 12-62%); (v) PND 11 male pup RBC at 40 mg/kg/day and above ( ↓ 32-78%); (vi) PND 11 female pup RBC at 40 mg/kg/day and above ( ↓ 31-77%); (vii) PND 11 male pup brain at 40 mg/kg/day and above ( ↓ 20-57%); and (viii) PND 11 female pup br ain at 40 mg/kg/day and above ( ↓ 19- 58%).

In the repeated dose study in the adul t female RBC, dose-related increases (p ≤ 0.01) in

ChE inhibition were observed at 25 mg/kg/day and above ( ↓ 22-91%). Decreases (p ≤ 0.01) in adult female brain cholinesterase activities were noted at 50 mg/kg/day and above ( ↓ 51-69%). In the pups, decreased (p ≤ 0.01) RBC cholinesterase activity were noted in males at 10 mg/kg/day and above ( ↓ 13-71%) and in females at 20 mg/kg/day and above ( ↓ 35-72%). Decreased (p ≤ 0.01) pup brain cholinestera se activity were noted in males at 20 mg/kg/day and above ( ↓ 11-46%) and females at 40 mg/kg/day and above ( ↓ 33-42%).

In the gestational study in the dam RBC, dose-related increases (p ≤ 0.01) in ChE

inhibition were noted at 30 mg/kg/day and above ( ↓ 52-99%). Dam brain ChE inhibition (p ≤ 0.01) was also observed at 30 mg/kg/day and above ( ↓ 19-84%). In the fetal RBC, dose-related increases (p ≤ 0.01) in ChE inhibition were not ed at 30 mg/kg/day in both sexes ( ↓ 20-92%). In the fetal br ain, dose-related increases (p ≤ 0.05) in ChE inhibition were also noted in both sexes at 30 mg/kg/day and above ( ↓ 9-49%), with the males being slightly more sensitive than females.

In the acute study, the LOAEL in adults was 50 mg/kg/day based on ChE inhibition

in the RBC and brain of females. Th e NOAEL was 25 mg/kg/ day. The LOAEL in the PND 11 pups was 40 mg/kg/day based on ChE inhibition in the RBC and brain of males and females. The NOAEL was 20 mg/kg/day.

In the repeated dose study, the LOAEL in adults was 25 mg/kg/day based on ChE

inhibition in the RBC of fe males (only sex tested). The NOAEL was 15 mg/kg/day. The LOAEL in the PND 11 pups was 10 mg/kg/ day based on ChE inhibition in the RBC of males. The NOAEL was 5 mg/kg/day.

In the gestational study, the LOAEL in dams and fetuses was 30 mg/kg/day based

on ChE inhibition in RBC and br ain. The NOAEL was 15 mg/kg/day.Bensulide Human Health Risk Assessment DP No. D428598

Page 93 of 97 This study is acceptable and fulfills the purpose of this non-guideline study. The study identified sensitivity (or lack thereof) in sub-populations (pregnant females, immature (PND 11) rats, or fetuses.

Appendix A.4. Lifestage Sensitivity to Bensu lide-Induced Acetyl Cholinesterase (AChE)
Inhibition in the RBC of Rats Following Oral Treatment

MRID #

Test Lifestage

Sex BMD 10 (mg/kg/day) Nearest Dose to

90% of Control (% of Control) FoldDifference b Conclusion

Acute a Pup vs Adult

49433502

Acute CCA Adult

Male 79.11 50 (99%) 100 (78%) 4.5 The pup is more sensitive

than the adult. 49433502

Acute CCA Pup (PND 11) Male 17.74 20 (91%)

49433502

Acute CCA Adult

Female 27.21 25 (95%) 50 (73%) 1.7 The pup is more sensitive

than the adult. 49433502

Acute CCA Pup (PND 11) Female 16.23 20 (88%)

Steady State Pup vs Adult

49466201 Repeated Dose

CCA Adult

Female 18.66 15 (94%) 25 (78%)

1.5 The pup is more sensitive

than the adult. 49466201 Repeated Dose

CCA Pup

Female 12.30 5 (93%)

Fetus vs Dam

49454001

Gestational

CCA Dam 12.01 15 (94%) 30 (48%) Dam vs male

fetus: 0.5

Dam vs

female fetus:

0.6 The fetus is not more

sensitive than the mother. 49454001

Gestational

CCA Male

Fetus 22.34 15 (101%) 30 (80%)

49454001

Gestational

CCA Female

Fetus 21.82 15 (100%) 30 (80%)

Pregnant vs Non-Pregnant

49454001

Gestational

CCA Dam 12.01 15 (94%) 30 (48%)

0.6 The pregnant female is not

more sensitive than the nonpregnant female at doses

relevant to risk assessment.

The level of acetylcholinesterase inhibition was exactly the same at 15 mg/kg/day and the steady-state POD is 6 mg/kg/day. 49466201 Repeated Dose

CCA Adult

Female (Not Pregnant) 18.66 15 (94%) 25 (78%)

a No data available to compare fetus vs dam or pre gnant vs non-pregnant lifesta ges following a single dose.

b Upper Row ÷ Lower Row of Merged Cell. When BMD did not agree with empirical evidence, the dose tested which provided

inhibition nearest 10% was used instead of BMD 10

.Bensulide Human Health Risk Assessment DP No. D428598

Page 94 of 97 Appendix B. Physical/Chemical Properties

Table B1. Physicochemical Properties of Bensulide and Bensulide Oxon

Parameter Value Reference

Bensulide Molecular weight (g/mole) 397.54 MRID 45761801 Melting point (°C) 36 MRID 41532001 Water solubility ( mg/L at 25°C) 5.6 MRID 41532001 Vapor pressure at 25°C (mmHg) 8.2 x 10 -7 MRID 41532001 Dissociation constant (pK

a ) Not Applicable Octanol/water partition coefficient Log(K OW ) 4.20 H. Zhong, D428601, 09/14/2015 (values modeled with EPI Suite, v 4.10)

Bensulide oxon Molecular weight (g/mole) 381.44 H. Zhong, D428601, 09/14/2015 (values modeled with EPI Suite, v 4.10) Melting point (°C) 89.97 Water solubility ( mg/L at 25°C) 461.24 Vapor pressure at 25°C (mmHg) 2.48 10 -8

Dissociation constant (pKa) Not Applicable Octanol/water partition coefficient Log(K O W ) 2.35Bensulide Human Health Risk Assessment DP No. D428598

Page 95 of 97 Appendix C. Review of Human Research

This risk assessment relies in part on data from studies in which adult human subjects were intentionally exposed to a pesticide or other chemical. Thes e data, which include studies from the Pesticide Handlers Exposure Database Vers ion 1.1 (PHED 1.1), the Agricultural Handler Exposure Task Force (AHETF) database and, the Aquatic use Standard Operation Procedure (20-Sep-2013) and are subject to ethics review pursuant to 40 CFR 26, have received that review, and are compliant with applicable ethics requirements. For certain studies that review may have included review by the Human Studies Revi ew Board. Descriptions of data sources as well as guidance on thei r use can be found at http://www2.epa.gov/pesticide-science-andassessing-pesticide-risks/occupati onal-pesticide-handler-exposure-data and http://www2.epa.gov/pesticide-scie nce-and-assessing-pe sticide-risks/occupational-pesticidepost-application-exposure

.Bensulide Human Health Risk Assessment DP No. D428598

Page 96 of 97 Appendix D. International Residue Limits Table



### Bensulide (PC Code 009801)

Summary of US and International Tole rances and Maximum Residue Limits
Residue Definition :

US Canada Mexico 2 Codex

40 CFR 180.241: (a) General. (1) -(O,O-diisopropyl phosphorodithioate) of N-(2-mercaptoethyl) benzenesulfonamide including its oxygen analog S-(O,O-diisopropyl phosphorothioate) of N-(2- mercaptoethyl) benzenesulfonamide None None

Commodity 1 Tolerance (ppm) /Maximum Residue Limit (mg/kg)

US Canada Mexico 2 Codex

Onion, bulb 0.10 Vegetable, brassica, leafy group 5 0.15 Vegetable, cucurbits group 9 0.15 Vegetable, fruiting group 8 0.10 Vegetable, leafy except brassica group 4 0.15

Completed: M. Negussie; 09/21/15

1 Includes only commodities of interest for this action. Tolerance values should be the HED recommendations and not those proposed by the applicant.

2 Mexico adopts US tolerances and/or Codex MRLs for its export purposes.

(c) Tolerances with regional regi strations. Tolerances with regional re gistration, as defined in §180.1(l), are established for the residues of S-(O,O-diisoprop yl phosphorodithioate) of N-(2-mercaptoethyl) benzenesulfonamide including its oxygen analog S- (O,O-diisopropyl phosphorothioate) of N-(2- mercaptoethyl) benzenesulfonamide in or on the following food commodities:

Commodity Parts per million

Carrot, roots 0.10Bensulide Human Health Risk Assessment DP No. D428598

Page 97 of 97 Appendix E. Comparison of Residue Levels of Bensulide and its Oxon

Table E summarizes residue data for commodities that do not have PDP data available for both parent bensulide and its oxon. The purpose is to provide information to address the dietary exposure and risk assessment. In addition, PDP data for lettuce (in which bensulide and its oxon were measured) were included.

Table E. Summary of Residue Leve ls for Bensulide and its Oxon Matrix (Reference) Use Pattern / PDP Sample ID Bensulide Bensulide

Oxon Factor (Oxon/Parent)

Tomato Metabolism (D179576, 04/21/1993) 8.6 lbs ai/A pre-plant 112-153 day PHI ND (86% TRR iden/char) ND (86% TRR iden/char) NA

Lettuce Metabolism (D1855889, 03/29/1993) 8.6 lbs ai/A soil pre-plant 67 day PHI ND (86% TRR extracted) 2% TRR (86% TRR extracted) NA

Carrot Metabolism (D177460, 06/02/1992) 8.6 lbs ai/A soil pre-plant 126 day PHI 30% TRR (94% TRR extracted) 2.8% TRR (94% TRR extracted) 0.09x

Squash Field Data (D218256, 01/24/1996) 9 lbs ai/A pre-plant ND 1 ND 1 NA

Cucumber Field Data (D218256, 01/24/1996) 9 lbs ai/A pre-plant ND 1 ND 1 NA

Bulb Onion (D206633, 11/29/1994) 9 lbs a.i./A pre-plant or preemergence Harvest at Maturity ND 1 ND 1 NA

Bell Peppers (D238521, 10/07/1997) 5-9 lbs ai/A pre-plant or

pre-emergence 109-129 day PHIs ND 1 ND 1 NA

Lettuce PDP Results (years 2010-2011) 2010-6721 0.005 0.01 2.0

2010-6845 0.004 0.005 1.3

2010-7044 0.014 0.12 8.6

2010-7052 0.005 0.008 1.6

2010-7265 0.014 0.023 1.6

2011-6295 0.012 0.003 0.3

1 The LOQ is reported to be 0.05 ppm.

Lettuce : The metabolism study with lettuce showed detection of the oxon but not of the parent bensulide which suggest that the oxon may pre dominate. PDP data for lettuce (years 2010 and 2011) shows that bensulide (LOD ≤ 0.014 ppm) was detected in 6 of 1487 samples whereas bensulide oxon (LOD ≤ 0.002 ppm) was detected in 49 of those 1487 samples. The samples in

which both were detected were included in the ta ble above in order to estimate the ratio of the concentration of the oxon with respect to parent bensulide. These factors range from 0.3 to 8.6. This data suggest a factor of 9x for oxon residues with respect to bensulide.

Other Crops (Non-Leafy): The metabolism study with tomato and carrot and the crop field trial data do not suggest that parent bensulide or the oxon may be present at significant concentrations. PDP data with summer squash, carrot and tomato was generated for bensulide and its oxon. Only two sample of tomato showed bensulide being detect ed; however, there were not detects of the oxon. This suggest that both residues of concern would be at low concentrations and that the oxon do not seem to predominate in these crops.